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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mathematical magic trick

Here’s a conversation that took place between two students. A: Hey, want to see a magic trick? B: Sure, how does it go? A: Think of any number. Any nonnegative integer, I should say. B: Okay. A: ...
user1134699's user avatar
4 votes
1 answer
660 views

Few enigmatic puzzles [closed]

?, 63264, 12825, 65121, 02420, 48409 REDYPS, Y = ? 8, 33, 5 : X, II, ? Gods in space (7 letters) = 51151 = 8812, 22334 = 8459, 99111 = 2110910, 27772 = ?
IdontKnowWhatNameToPut's user avatar
4 votes
1 answer
732 views

Numbers turned into a number turned into numbers (start with the smallest)

What number should replace the question mark? Explain why. Hint 1
Prim3numbah's user avatar
4 votes
2 answers
190 views

Strings of Kind Numbers

A positive integer is said to be “kind" if it is divisible by one of its digits other than 1 (https://oeis.org/A185186). A kind string of numbers is a finite sequence of numbers all of whose ...
Bernardo Recamán Santos's user avatar
5 votes
1 answer
244 views

Simple number sequence puzzle

Complete the sequence: 8, 6, 7, 3, 6, 5, 4, 5, 5, 2, ?
someone_else's user avatar
11 votes
1 answer
564 views

List Roman numerals to minimize total distance

This is based on a discussion with @mousetail. List the numbers from 1-100 in Roman numerals in the order that minimizes the total sum of the Levenshtein distances between consecutive numbers.
Simd's user avatar
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0 votes
1 answer
131 views

Relation Between The Year And The Day

Today is January 22, the 22nd day of the year 2024. I chose today because 22 is my favorite number. Now for the problem. Try to relate 22 to 2024 using math. For example, 58 is related to 271 because ...
Ronchen Luo's user avatar
10 votes
1 answer
1k views

What is the earliest 2024 can appear in an S-sequence?

A Sloane Sequence (or S-sequence) is any sequence of different positive integers begining with 1 in which the nth term (after the first) is the previous term plus n, times n, minus n, or divided by n ...
Bernardo Recamán Santos's user avatar
12 votes
2 answers
636 views

Arithmetic-progression-free sequences

This question Sudokus with no 3-term arithmetic progressions within made me wonder about the following question. What is the longest sequence composed of the integers 1..N (or 0..N-1 if you have a ...
Florian F's user avatar
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-1 votes
1 answer
162 views

icosahedral net [closed]

The net of $20$ triangles shown to the right can be folded to form a regular icosahedron. Inside each of the triangular faces, write a number from $1$ to $20$ with each number used exactly once. Any ...
godlification's user avatar
2 votes
1 answer
297 views

Number sequence puzzle: strings of 0s and 1s

How can I solve this sequence? 011010, 100010, 100010, 100010, 000010, ?, 100010 https://free.ultimaiq.net/nse.htm
Simi 's user avatar
  • 23
2 votes
0 answers
299 views

What's the missing number related to primes?

I would like to draw your attention to this mathematical sequence related to prime numbers I've created and ask what the missing number is. 2, 5, 27, 182, 2310, 27200, ______, 8998400, 223092870, ...
Ruleft's user avatar
  • 29
1 vote
1 answer
342 views

Two number sequence puzzles

123456, ?, 32407290, 128028806480 122540, 577697, ?, ? Both puzzles are from - https://free.ultimaiq.net/nse.htm
Fraternal9274's user avatar
1 vote
2 answers
265 views

Numeric progressive matrix: 2-7-5, 2-3-4, 10-21-?

This is an interesting question that I got from an IQ interview test. This can have multiple answers but need a good explanation.
Chau Giang's user avatar
8 votes
2 answers
834 views

A very presentable number sequence

(The title holds a clue) 12,22,30,36,40,42,42,40… Here is a finite sequence. Can you tell me the sum of all of its numbers?
PDT's user avatar
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8 votes
1 answer
518 views

Find the pattern of the sequence of prime numbers 17 23 5 1013 2027 13

A friend gave me a sequence of prime numbers 17 23 5 1013 2027 13 and said that they have a pattern. I tried to find something but I am stumped by the fact that the numbers first increase, then kill, ...
whoisthat's user avatar
5 votes
1 answer
301 views

What are the next 3 terms: 19, 43, 59, ...?

What are the next 3 terms in the following finite sequence? 19, 43, 59, 23, 79, 83, 109, 463, 569, 263, ?, ?, ?
Dmitry Kamenetsky's user avatar
34 votes
1 answer
1k views

A number sequence in disguise

What number should replace the question mark? Explain why. ...
Prim3numbah's user avatar
-1 votes
1 answer
130 views

Numbers given: 2, 3, 6, 15, choice of answers: 24, 25, 36, 64? [closed]

Math question, numbers are 2. 3. 6. 15 Choice of answers given are A.24 B.25 C.36 D.64 What is the correct choice please?
PaulaT.'s user avatar
  • 17
0 votes
1 answer
180 views

Find the wrong number in the given series

I found this question in an Indian Highschool Reasoning Olympiad. I tried looking for any relation using powers of 2 but failed.
Darshit Sharma's user avatar
3 votes
1 answer
376 views

Find the correct pattern in this series

My uncle send me a puzzle, and neither of us can solve it. The series seems to have an obvious pattern, however the given answers do not include that pattern. -2, 4, -6, 8, -10, 12, ..., ... a) 39, ...
Chris_abc's user avatar
  • 139
20 votes
2 answers
1k views

A symmetrical number sequence

What 5-letter word does this sequence represent? ...
Prim3numbah's user avatar
-7 votes
1 answer
175 views

Need help solving two number puzzles

1st Puzzle: Can you find the next two numbers in the sequence: 122540, 577697, ?, ? 2nd Puzzle: Solve this sequence: 28) 123456, 777, 154, ?, ? Both questions are from https://free.ultimaiq.net/nse....
IdontKnowWhatNameToPut's user avatar
1 vote
5 answers
2k views

What is next letter in sequence: B, D, G, J, L, ___?

My answer is P. But I am not sure as there is not sufficient data to support this. B(2), ____, G(7), ____, L(12), _____ (alternating sequence of difference 5: 2, 7, 12, 17,...) ____, D(4), ____, J(10),...
Mohit Vijay's user avatar
5 votes
1 answer
580 views

What is the next number in the following sequence: 0, 4, 8, 21, 52, 65, 96,?

What is the next number in the following sequence: 0, 4, 8, 21, 52, 65, 96, ? To allow new users to solve this puzzle and earn reputation points, I encourage all users whose reputation is 200 or ...
Will Octagon Gibson's user avatar
2 votes
1 answer
138 views

If 123x45 = 1, 22+222=0, 8979:4=5, 56319=2 what is 781-32=?

If 123x45 = 1, 22+222=0, 8979:4=5, 56319=2 what could be the solution to 781-32=? Found it on an maths board and became desperate over time.
Guestos's user avatar
  • 29
6 votes
1 answer
499 views

A healthy number sequence

What should b the missing number? 1, 2, 3, 5, 6, 7, ?, 12
Dmitry Kamenetsky's user avatar
2 votes
1 answer
962 views

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
2 votes
3 answers
342 views

Next term in sequence [closed]

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
105 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
6 votes
1 answer
391 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
15 votes
1 answer
634 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
  • 613
4 votes
1 answer
459 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
1 vote
0 answers
192 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
  • 11
-4 votes
2 answers
419 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
3 votes
1 answer
135 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
186 views

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
  • 21
1 vote
3 answers
381 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
3 votes
2 answers
190 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
  • 6,657
2 votes
1 answer
187 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
  • 1,649
5 votes
1 answer
391 views

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
  • 59
4 votes
1 answer
427 views

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
  • 808
1 vote
1 answer
343 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
  • 4,906
6 votes
1 answer
254 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
10 votes
1 answer
907 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
  • 6,049
-5 votes
2 answers
140 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
170 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
7 votes
1 answer
292 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
  • 2,208
6 votes
1 answer
948 views

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
  • 699
3 votes
1 answer
595 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:
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