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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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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
867 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
  • 4,011
-5 votes
2 answers
119 views

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
141 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
268 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
  • 631
4 votes
0 answers
753 views
+50

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
  • 669
2 votes
1 answer
282 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
153 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
156 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
296 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
258 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
  • 591
18 votes
1 answer
702 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
  • 41.4k
1 vote
2 answers
162 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
  • 591
2 votes
1 answer
175 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
  • 21.8k
11 votes
1 answer
283 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
  • 591
3 votes
1 answer
191 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
  • 591
3 votes
1 answer
401 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
152 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
196 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
379 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
229 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
886 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
  • 20.7k
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
909 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
  • 4,011
-4 votes
1 answer
248 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
276 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
227 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
  • 1,270
12 votes
1 answer
717 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
339 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
  • 1,103
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
139 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
  • 6,935
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
218 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, ? I was asked this on an interview. My time ran out and I couldn't figure out the pattern. I am spotting a lot of $3^n + 1$ terms here maybe that is helpful ...
CharlieCornell's user avatar
17 votes
1 answer
4k views

Radical IQ challenge

This puzzle is part of the Monthly Topic Challenge #2: IQ Puzzle Parody Can you find out the next one in the sequence, how it's different to the ones before it, and explain the pattern? 1 10 11 20 31 ...
PuzzlingFerret's user avatar
5 votes
1 answer
297 views

There are a lot of gifts missing

1-108-121-128-146-157-195-227-305-315-??? There are a lot of gifts missing There is a missing 11th number which is it? This is not on OEIS :)
JKHA's user avatar
  • 5,971
8 votes
2 answers
588 views

A number association puzzle

These 0 to 10 digits are associated with the specific numbers as shown below. What are the associated numbers for digits 9 and 10? Why? Bonus: Is there an associated number for 11?
RogerA's user avatar
  • 4,011
3 votes
1 answer
1k views

Decode 'xorarlpziebpwanywxnf' to find the hidden message

Try to find the hidden message in the text: xorarlpziebpwanywxnf These seemingly random numbers will help you solve the puzzle: ...
Justiniscoding's user avatar
14 votes
1 answer
2k views

A strange number pattern, isn't it?

This looks like a strange number sequence to me. Or is it? 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 20 21 22 23 24 25 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 ? ? ? ? ? So what are ...
DrD's user avatar
  • 39k
0 votes
0 answers
72 views

I promise, never again! [duplicate]

The first 15 non-negative integers are written below. The 16th number contains 4 digits! - yet it is the next and the last term. No special knowledge required. Try see if you can find a pattern and ...
Prim3numbah's user avatar
  • 23.7k
2 votes
2 answers
229 views

Planar Investigator

Use logical deduction to place a different digit from 1 to 9 in each circle below so that 8 of the arrows form the primes 23, 31, 41, 53, 59, 79, 89, and 97. (We view an arrow starting at digit A and ...
noedne's user avatar
  • 15.3k
2 votes
1 answer
261 views

What's the next term in this sequence?

I created this simple number sequence puzzle, I don't know if anyone used the same idea before. Find the term at the question mark in the sequence. $$ 25, 42, 56, 97, 176, 232, 251, 269, 394, 518, 572,...
user avatar
0 votes
1 answer
178 views

A simple number sequence puzzle

This is a simple number sequence puzzle, you are given 6 related number sequences, observe them, find the pattern; Your task is to give the first sixteen terms in the seventh sequence. $$1d5, 2d3, ...
user avatar
11 votes
1 answer
332 views

Gah, these number sequences are just too boring!

Gah, these number sequences are just too boring! You just plug them in and then you're done! There is a function $f : \mathcal{S} \to \mathbb{Z}$, where $\mathcal{S}$ is a finite subset of the ...
flame's user avatar
  • 815
8 votes
1 answer
962 views

I can't remember her birthday!

My Persian friend said: I will meet you in New York on my birthday. But I can't remember her birthday! I only found this riddle related to her birthday in old chats. $(y+z)/y = (y)/z = (A+10)/10 $ $...
Marzieh Mousavi's user avatar
18 votes
1 answer
1k views

Describe your ability to solve this number sequence!

Here is a sequence of numbers: 0, 2, 4, 6, 8, -, -, -, 10, 12 Can you fill in the three blanks and thus reveal your excellent puzzle-solving ability?
chasly - supports Monica's user avatar
0 votes
1 answer
359 views

What is this sequence? 1, 11, 21, 22211, 33221

In this sequence: 1, 11, 21, 22211, 33221, 433332211, 44444444332221, ? Can you guess the next number? What is this sequence? Hint 1: Hint 2:
Fmbalbuena's user avatar
7 votes
1 answer
237 views

How do you go from 2021 to 2022?

Below a path is shown that goes from 2020 to 2021. Following the same path, how do you go from 2021 to 2022? 2322, 2302, 2012, 2020, 2028, 2025, 2024, 2029, 2021, ..., ..., ..., 2022 Fill the gap.
Florian F's user avatar
  • 25.1k
0 votes
2 answers
208 views

What should be the most logical and appropriate 9th term in this sequence?

Consider this sequence 3, 5, 10, 20, 39 What is the pattern? I initially thought it might be a pattern of *2-1, *2,*2,*2-1 (a group of *2-1,*2,*2 repeating itself), but don't think this is a valid ...
Orion_Pax's user avatar
  • 101
3 votes
1 answer
126 views

Very long number sequence

Here is the sequence: ...
khang2009's user avatar
  • 167
9 votes
1 answer
400 views

Complete the rest of this seasonal sequence

Usually I don't like this kind of "guess the next terms" puzzle. But at this time of the year I wonder whether it makes sense to post such a question. So here is the start of a sequence: $$...
WhatsUp's user avatar
  • 7,229

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