Questions tagged [number-sequence]

A puzzle in which the hidden pattern behind a given sequence of numbers (and, often, the next term) is to be found. Use with [sequence]

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What is the next term in the sequence 3, 1, -7, 41?

I could detect only one pattern, however, the sign is confusing me $3 - 1 = 1 \times 2$ $1 - (-7) = 2 \times 2^2$ $-7 - 41 = -3 \times 2^4$ I have a pattern, but I am confused due the to sign.
Mohit Vijay's user avatar
0 votes
1 answer
127 views

Next term in sequence

Came across these 3 sequences to find the next number denoted by '?' in a test yesterday and was unable to select the right answer from the options given 1,6,19,54,151,426,? - Options given are 1415,...
quantrader23's user avatar
1 vote
0 answers
68 views

Can you find the missing letters?

A pattern of letters has had letters 10 through 20 deleted. Your job is to find out what letters should go in spots 10-20. Here is the pattern: a, b, c, d, d, d, f, e, f, _, _, _, _, _, _, _, _, _, _, ...
BigMistake's user avatar
-1 votes
0 answers
236 views

Find the ciphering method 3

Link to the entire series. The message: ...
web adventurer's user avatar
4 votes
1 answer
326 views

Find the ciphering method 2

Link to the entire series. The message: 3, 53, 48751, 9247757, 294914580539 The answer is a 13 letter word: UNDERSTANDING Hint 1:
web adventurer's user avatar
13 votes
1 answer
602 views

Self-referential sequence that is sometimes powers of two

I've created an integer sequence where, after the first two elements, every element is calculated using the previous two. If the first two numbers are $1$ and $3$, the sequence goes as follows: $$1, 3,...
Peter's user avatar
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3 votes
1 answer
293 views

Find next element of the sequence

Source of the question: Taken from the sub-Reddit r/askmath here: https://www.reddit.com/r/askmath/comments/15ar3ne/looking_for_the_answer_to_the_following_sequence/ What is the next element of the ...
user85272's user avatar
0 votes
0 answers
176 views

Puzzle Challenge: Unraveling the the Circular Conundrum

Known are five numbers: 1, 2, 3, 4, and 5, arranged clockwise. The number after 1 is 2, after 2 is 3, after 3 is 4, after 4 is 5, and after 5 is 1. Whenever two adjacent numbers meet, it triggers a ...
Kevin's user avatar
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2 answers
405 views

4, 2, 4, 2305843009213693952, ? - an original number sequence

Here is the sequence: 4, 2, 4, 2305843009213693952, ? Source: My brain (as it was invented by me. I also attempted to search if someone else created this, but I was unable to find) Hint 1: Hint 2: (...
Qaer Kyr's user avatar
2 votes
1 answer
131 views

Find the next term in the sequence [closed]

What's the next term in the sequence? $12$, $28$, $36$, $84$, $88$, $168$, $\ldots$ The possible choices are: $174$, $170{2\over3}$, $188$, $169{1\over3}$, $176$
user85175's user avatar
-4 votes
2 answers
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If ABCDE*4 = EDCBA. A,B,C,D and E are all natural numbers ( 1-9) without repeating any natural number. Why is it deducible that E cannot be three?

If ABCDE*4 = EDCBA. ABCDE,EDCBA are five digit numbers. A,B,C,D and E are all natural numbers ( 1-9) without repeating any natural number. Why is it deducible that E cannot be three?
jkj's user avatar
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3 answers
378 views

The following sequence contains a 12 somewhere

Consider the following sequence: 11, 6, 11, 11, 6, 11, 11, 6, 11, 6, 6, 11, 6, 11, 11, ... Although it looks like a sequence of 6s and 11s at first, it will in fact eventually contain a 12. Also, it ...
Geoffrey Trang's user avatar
2 votes
2 answers
166 views

Mathematical Codebreaking

I've created a number-sequence puzzle and dressed it up as a cipher puzzle. The following message has been intercepted. You suspect it begins with the words ...
codewarrior0's user avatar
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1 vote
1 answer
173 views

Enclosed yet another sequence

There are so many sequences here already, I cannot guarantee that this is new. At least, I haven't found anything like this yet. But I can assure you that you will not find the sequence on OEIS. $$ 0, ...
theozh's user avatar
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3 votes
1 answer
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Why do 1 and 1 complete 120, 10, 3, ?,?

This is a question from an IQ test (NSE test designed by Ivan Ivec and Theodosis Prousalis). The link for this test is https://free.ultimaiq.net/nse.htm The sequence is: 120, 10, 3, ?, ? The answer ...
Von's user avatar
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3 votes
1 answer
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Find the next digit in four given sequences

Find the next digit in each of these four sequences: 7 8 8 8 8 ... 3 4 5 2 5 ... 2 1 2 1 2 ... 1 1 9 6 3 ...
David's user avatar
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0 votes
1 answer
332 views

Restore a once very happy sequence

Once, I had a nice sequence of numbers.. They were all very happy. Suddenly, someone came by and stole all the lines. The numbers didn't know what to do, and got very scared. They clung to each other. ...
Lezzup's user avatar
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5 votes
1 answer
248 views

Self-numbers and repunits

Self-numbers or Colombian numbers (A003052 in the OEIS) are natural numbers which are not the sum of a smaller number and the sum of its digits. Repunits (in base 10) are numbers consisting only of 1'...
Bernardo Recamán Santos's user avatar
9 votes
1 answer
899 views

How is the RHS related to the LHS

Please explain the following relationship: Accessible: 2 --> 18 20 --> 48 200 --> 6 2000 --> 26 How did I arrive at these?
RogerA's user avatar
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-5 votes
2 answers
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An interesting Number sequence: 8, 10, 7, ...? [closed]

Let's see how many of you can solve this correctly I found a number sequence puzzle somewhere in the web with interesting logic and a unique strict solution. 8, 10, 7, 12, 5, 16, 3, ?
Guest user's user avatar
1 vote
1 answer
162 views

Continue the row of numbers: 1, 3, 9, 13, 65, ...?

Yesterday, I stumbled across a series of numbers that I could not solve. Maybe one of you can figure it out? 1, 3, 9, 13, 65, …?
HeterPawker's user avatar
6 votes
1 answer
283 views

Find the next number in these series..?

1, 1, 1, 1, 2, 2, 2, 2, 2, 5, 4, ? 2, 4, 6, 10, 15, 26, ? 71, 194, 38, 1701, 89, 76, ? 5303944, 6677714, 2070936216988528558, ? 1, 2, 3, 6, 9, 9, 16, 20, 18, 30, ? You know, there is more than ...
poco's user avatar
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5 votes
1 answer
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Given the length of sequences with different seed values, what comes next? 1, 2, 4, 5, 11, 22, etc

Edit: Apparently this site has had a few too many what comes next puzzles without anything to go off of so I've decided to make this a different albeit a bit easier puzzle. Sequences generated by a ...
MilesZew's user avatar
  • 689
2 votes
1 answer
325 views

1, 2, 3, 10, ... Another find-the-next-number-in-the-sequence puzzle

Can you spot the pattern and continue the following sequence? 1, 2, 3, 10, 12, 16, 25, 37, 55, 81, 100, ... Hints:
Dennis_E's user avatar
  • 1,199
-2 votes
1 answer
164 views

What is the next number in the sequence below [closed]

6.000,7.000,.857,8.168,.105,77.790 Which of the following responses completes the series .001 740.857 9.524 .013
Stella Schinnour's user avatar
0 votes
0 answers
165 views

Two number patterns (clue: or geometrical shapes)

Solve the series: Series 1: 6 and 1 5 and 2 4 and 3 5 and 1 ??? Series 2: 6 and 1 5 and 2 5 and 1 4 and 3 ???
Erin's user avatar
  • 141
3 votes
1 answer
492 views

The "Slightly Spooky Sequence" Game

Two players, Alice and Beatrice, having previously agreed on a positive integer N (say 30) as a limit, take turns to write a sequence of positive integers. In the first turn Alice writes 1. Thereafter,...
Bernardo Recamán Santos's user avatar
6 votes
1 answer
264 views

Same sequence interwoven with itself creating groups

If we take all the digits from 1 to 9 and lay them out in order. 123456789 Now repeat the sequence and add it to the end. 123456789123456789 Now let's copy and reverse everything to create a second ...
Maff's user avatar
  • 601
19 votes
1 answer
733 views

What is the last integer in this sequence?

Here are the first several entries in a finite sequence of integers. $$ 31, 45, 71, 89, 91, 94, 111, 112, 118, 121, 126, 131, $$ $$ 134, 135, 139, 143, 144, 145, 148, 158, 161, 189, 193, 194, \dots $$ ...
Rubio's user avatar
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1 vote
2 answers
177 views

How Many Magic Hexagons that use repeated digits?

There exists only 1 normal magic hexagon that uses non repeating consecutive digits for 1 to 19. If We allow digits to repeat we can create something like this hexagon that is made up using ...
Maff's user avatar
  • 601
2 votes
1 answer
179 views

More bits the merrier

The computer department at Puzzled State University devised an inefficient bit-based (zeros and ones) number system, n', for their ever more bit-happy machines. ...
humn's user avatar
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12 votes
1 answer
288 views

Square Sum Problem Summing 3 consecutive digits along the line

In this image from a numberphile video we see a sequence of numbers from 1 to 15 without repeats where any pair of neighbouring digits sum together to make a perfect square number. 15 is the lowest ...
Maff's user avatar
  • 601
3 votes
1 answer
211 views

Smallest 3x3 Magic Square of different square sums

Consider the follow magic square highlighted in yellow. The sum of its rows and columns are in green and the sum of the diagonals in red. All of its sums are a square number with the sum of the whole ...
Maff's user avatar
  • 601
3 votes
1 answer
406 views

please Extend this list of Units

Given the following list of four corresponding series of numbers, what would the fifth line look like? 1 : 1.4 / 3 2 : 3 / 2 | 1 : 2 / 6 2 : 3 / 2 1 : 2 / 3 Hint 1: This puzzle was inspired by the ...
Janus Bahs Jacquet's user avatar
3 votes
0 answers
160 views

Odd one's out (sequence)

Once upon a time, there was a curious mathematician named Friedrich. One day, while exploring a new area of mathematics, he stumbled upon an intriguing sequence of numbers: 0, 1, 2, 2, 4, 3, 3, 4, 4, ...
Rubén's user avatar
  • 31
3 votes
1 answer
199 views

A Weird Sequence

Today, I was in Rome for a vacation. The most peculiar thing happened. A gnome walked up to me. Uttering no words, it handed me a slip of paper. 0, 1, 1, 2, 3, 2, 5, 5, 5, 9, 4, ? Naturally, I was ...
shreyasm-dev's user avatar
2 votes
1 answer
387 views

Another predictable sequence: 1, 1, 2, 2, 1, 17, etc

This puzzle is part of the Monthly Topic Challenge #6: Is it really that [time] again?. Can you find the pattern? Note: The next number hasn't been worked out yet. ...
Scratch---Cat's user avatar
1 vote
1 answer
232 views

What are the missing numbers in the circle?

Given the following diagram, what are the missing two numbers in the last figure? This is from a mathematics book for primary school
M.M's user avatar
  • 111
13 votes
1 answer
892 views

Twelve numbers omitted

This is the beginning of a simple sequence. NO Computers or special knowledge are required. Insert the missing numbers. Explain how the sequence was generated. Note: the line breaks can be ignored, ...
Amoz's user avatar
  • 23.1k
59 votes
1 answer
56k views

My dead mom left behind some number code

Background: I actually do not know the answer to this puzzle, but can answer any questions you may have. My mom who is now deceased had this series of numbers written in her notebook, that don't seem ...
Cain Smith's user avatar
10 votes
1 answer
915 views

Will the sequence ever change?

Here is a sequence that seems to go on forever. Will it? Will this sequence ever change? 1,2,3,1,0,1,2,3,1,0,1,2,3,1,0 and so on What does this sequence relate to?
RogerA's user avatar
  • 4,641
-4 votes
1 answer
276 views

Chinese Pinyin Puzzle

Puzzle World in VR Chat. Must Select the 8 Words in the right order 1-8. Nothing other than that I'm aware of.
Puzzles4Fun's user avatar
3 votes
1 answer
296 views

What is the next number in the series 1111111,111,21,13,12,11,10? [closed]

Find the next number in the series 1111111,111,21,13,12,11,10, [There was a hint saying the answer is a single-digit integer, and the series has something to do with the number 7] I've only been able ...
Qusai_N's user avatar
  • 35
3 votes
1 answer
234 views

Two naughty programmers

The math professor wrote an equation f(x) = x and defined t as number of solutions at f(x) = 5 and u as number of solutions at f(x) = 3. He further defines N as N = t+u Two programmers decided to edit ...
I'm Nobody's user avatar
  • 1,304
13 votes
1 answer
798 views

What is the sequence?

The following 5 sequences of base-10 numbers all follow the same pattern, and converge at 14,. What is the pattern and which number is next? 1,5,10,14,23,... 2,6,10,14,23,... 3,9,14,23,... 4,9,14,23,.....
simonalexander2005's user avatar
2 votes
1 answer
346 views

German number sequence

Classical format, here is a sequence of numbers, you need to find out how it continues: 5, 4, 14, 8, 0, 4, 2, 2, 2, 0, -3, -1, -2, -3, -7, -7, -6 This puzzle should also have the tag 'Germany' ...
quarague's user avatar
  • 1,309
13 votes
1 answer
2k views

Mom Got Me Shoes For My Birthday

What number must replace the question mark below? 218 19 780 17 11 9,000 301 6 8 600 ? 80 70
JLee's user avatar
  • 17.5k
1 vote
0 answers
142 views

An increasing decreasing sequence

In math, there are all kinds of sequences 1545, 1218, 1071, 921, 851, 832, 799, 793, 774, 745, ... is (the start of) such as sequence What is the best number? Note: Even in math things change, so ...
Retudin's user avatar
  • 7,609
3 votes
3 answers
182 views

Balanced binary cycle

Let's call a binary cycle ${\bf x}:x_1,x_2,\ldots, x_{12}$ balanced if exactly 6 of the $x_i$'s are 0 and 6 of them are 1. We can place the sequence around a circle and add each two adjacent digits ...
Marco's user avatar
  • 131
2 votes
1 answer
304 views

Next number in the sequence 2, 4, 3, 10, 5, 5, 28, 11

2, 4, 3, 10, 5, 5, 28, 11, 7, 8, 82, 29, ? What is the next term in this sequence? I was asked this in an interview, but my time ran out and I couldn't figure out the pattern. I see a lot of terms of ...
CharlieCornell's user avatar

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