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]

A 'number sequence' is a series or collection of numbers presented in a particular order according to a specific logical rule. In puzzles, the aim for the solver is usually to deduce or discover the rule behind this ordering, and/or supply the next - or missing - number(s) in the sequence.

The hidden pattern is often mathematical in nature (in which case, the tag may also be used), but sometimes is derived from common knowledge, structures (e.g. Morse code), or language (e.g. alphabetical ordering).

For some advice on how to create interesting number sequence puzzles (and also what not to do), see this meta question.

Please note: Many common "brainteaser" number sequences, such as the "Look and Say" sequence, have already been posted on Puzzling Stack Exchange. Before sharing an interesting sequence that you have found published or presented elsewhere, please make sure to search for duplicates using at least the first few terms of the sequence, and avoid re-posting questions found to have been posted previously.

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It's my birthday

Just like last year, my age is a number you can score with one dart. The year before that, it wasn't, and it won't be next year. How old am I?
Rupert Morrish
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A very simple puzzle: 1,1,2,1,2,2,3

Here's a simple puzzle, I know that you will find. As long as you can count, It shouldn't take much time. 1 1 2 1 2 2 3 1 2 2 3 Find the next 4 numbers in this sequence.
Kingrames
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That gap is a bit jarring

... but there doesn't seem to be anything missing. $0,1,2,3,4,5,6,7,1527465$ What then could cause that rather large gap?
zennehoy
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How is this number sequence built up and how does it continue?

Can you work out how this number sequence is built up? Can you work out how it continues? 1, 1, 2, 4, 8, 20, 60, 240, 1500, ....... Hint 1 this is a mathematical puzzle Hint 2 It does not involve complicated mathematics From time to time…
tom
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What does this group of numbers represent?

How is this set of 8 numbers - $6, 8, 15, 20, 36, 48, 90$, and $120$ - derived? I could provide hints but it would make it too easy.
Moti
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Number-sequence puzzle where the number goes down in the middle

My friend asked me for help with an IQ test and after she did it online she came back at me with the ones she couldn't solve. Two of them however, I discovered are the same puzzle type, but no matter how much I look at it, I just can't see the…
Folaht
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Can you generate the next number in this integer series and describe the rule?

2, 3, 5, 7, ... 11, 13, 17, ... 25, 29, ... 35, ... 43, 47, 49, ... 53, 59, 61, 65, 67, ... 71, ... ?? The answer (indicated by two question marks) has two digits. When you see '...', it means that one or more numbers are deliberately concealed…
chasly - supports Monica
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Explain the number sequence and predict the next 6 numbers

Given the number sequence 0,1,4,9,0,1,9,1,4,2,1,3,0,4,1,5,4,6,9,7,0,9,9,a,4,?,?,?,?,?,? the challenge is to Determine the value represented by a Predict the next 6 entries represented by ? Note that This number sequence does not appear in the…
tom
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Find the next number in the sequence: [12, 13], 25, 58, 52, 98, 108, 780, 568, 306

Given this sequence: [12, 13], 25, 58, 52, 98, 108, 780, 568, 306 What is the next number? Note the square brackets. Hint: This sequence follows the exact same rules: [10, 10], 10, 10, 10, 10, 10, 10 Hint #2: You only need two math operators…
MilesZew
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250 Floor Tower

There's a tower in a far off land, one that you can only climb by unlocking the secret password to all the floors. Each floor has an inscription on the walls, indicating a number. As you approach a bird screeches at you: I sit upon this enigmatic…
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Yet another number sequence puzzle

Number sequence puzzles are very popular of late. Therefore, I present to you another one. I promise you it has no relation to any sequence in OEIS, nor will it ever be found there, and it does not require any mathematics at all to be…
Glorfindel
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A Simple Number Sequence

What would be the next digit that follows these numbers? 1, 11, 20, 30, 7, 49, 42, 23, 3, ? Just so it's clear, you won't need any mathematics to solve this at all! In fact, everything you need is here.
Xenocacia
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Can you explain this cyclic number sequence

Can you work out the mathematical rule for this cyclic number sequence? 2, 6, 186, 8, 456, 54, 53, 23, 7, 301, 3, 21, 2, 6,..... Hint 1 this is a mathematical puzzle From time to time hints will be updated. Note: this sequence cannot be found…
tom
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Finding Sequence in Third Square

This particular puzzle is throwing me off for some reason, given that solutions I've tried for similar problems are not working. Problem Given that you have this square: .14 .21 .22 .17 .26 and this one: .4 .3 .0 .2 .1 What should…
Jeff Nyman
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A grounded number sequence

There is no external source required, this relies only on maths. Each line is independent from the others. Can you find the pattern and fill in the blanks ? 1 : 0 0 0 2 : 1 2 3 3 : 4 2 9 4 : 1 2 3 5 : 7 7 9 6 : 4 0 6 7 : 2 4 9 8 : _ _ _ 9 : 7 5…
Red-Jeweled
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