Questions tagged [number-sequence]

A puzzle that asks for the pattern in a given number sequence.

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IX-NAY on the IX-SAY

Will this sequence ever have a 6 in it? 9, 1, 1, 1, 10, 3, 1, 1, 10, 5, 1, 1, 10, 1, 5, 2, 1, 1, 10, 1, 1, 1, 5, 4, 1, 1, 10, 3, 1, 1, 5, 1, 1, 1, 5, 2, 1, 1, 10, 5, 1, 1, 5, 3, 1, 1, 5, 4, 1, ... ...
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Staying grounded

I found a somewhat meaningful sequence that is not on OEIS yet, incredible! Here are the first 100 numbers of this sequence: ...
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589 views

What is the next number? (an accounting interview question)

I got this question from an accounting interview: What is the next number? 0 1 3 8 56 65 ? What are the rules of the sequence?
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1answer
849 views

What is the next integer in this sequence?

First, I offer you a little something to put you in the right spirits: For many many years, black cats have had some interesting associations and reputations, which no doubt helped inspire The Black ...
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566 views

Next line in triangular sequence

$$ \small \begin{array}{c} 1\\ 1 & 2\\ 1 & 3 & 2\\ 1 & 3 & 2 & 4\\ 1 & 5 & 2 & 4 & 3\\ 1 & 4 & 2 & 6 & 3 & 5\\ 1 & 6 & 2 & ...
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Pattern 1 — Numbers

Fill in the missing number: 10, 30, 60, 01,__, 12 Use a bit of lateral thinking. And math. Also, I do know the answer. Just giving the question as a teaser.
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Another number sequence

Any ideas of what comes next? 0, 0, 1, 5, 119.... Note: this sequence cannot be found in The On-Line Encyclopedia of Integer Sequences and the solution is not obtained by fitting a polynomial ...
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20 cards facing down

You have a row of $20$ cards facing down. A 'move' consists of the following actions performed in sequence: Pick a face-down card and flip it face-up If there is one, also flip the next card on ...
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1answer
205 views

The mage's safe

After fighting hordes of undead, slaying several gargoyles and finally dispatching of the evil necromancer himself, the adventuring party finds itself in the treasure vault beneath the mage's tower. ...
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448 views

Find the next number and what I am!

This is the first puzzle I made and apparently it's too difficult. So I tried to create hints, but it's hard. If you have any ideas on how to write this riddle in a better way, or have more "...
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I need help with this number sequence

Okay, so I was reading my local newspaper, and they had an article about a pub quiz, which had the following sequence: 762 - 774 - 571 - 742 - 629 - 796 - 794 - 861 And the question was to figure ...
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What is the Ternary Sequence™

The sequence below, I call the $\text{Ternary Sequence™}$. \begin{gather*} \text{T}(1) = 1\\ \text{T}(2) = 2\\ \text{T}(3) = 5\\ \text{T}(4) = 5\\ \text{T}(5) = 3\\ \text{T}(6) = 5\\ \text{T}(7) = ...
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Sequence - stop at 90

You start with 0 and then proceed as follows: 1, 8, 2, 1, 11, 9, 18, ??, 90 There's no other number after 90 in this sequence. In fact, it's impossible to find! One of the numbers can be replaced ...
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A basic calculator, a simple game. What was I playing at? [duplicate]

Yesterday I was doodling around with my very simple calculator as shown in the picture. First I would enter a few digits to make an integer (i.e. no decimal places). Then I would perform a simple ...
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436 views

A sequence defined by a single fraction

I have a sequence of numbers here, which follow a very simple rule that can be expressed using a single fraction: 1, 2, 10, 11, 13, 15, 20, 22, 25, 28, ... What is this rule (in particular, what ...
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1answer
292 views

History function

Can you tell the next element of this history function? It is meant and important that mathematics tag isn't here! I save you the time to search on OEIS, you won't ...
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A poem and a number sequence

You wake up on the floor of an empty room without having any recollection of how you got there. The room is very dimly lit and it takes a while before your eyes are adapted to the darkness. There is ...
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163 views

Producing Integers

Came up with the idea for this one while I was scratching my head over another "what comes next" puzzle here on Puzzling.SE I wrote a small application which takes an integer and returns ...
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4answers
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Find the missing number in this transformation

I've recently come accross this puzzle. 2,5,8 = 122348 3,5,4 = 181224 7,4,6 = 352230 5,3,10 = 203340 3,9,4 = ? I was able to figure out 30**40 but couldn't ...
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872 views

Hidden Number Sequence

Oh! Please help. There is a number sequence hidden in here, but where? Here are just a few examples so I will make the answer multiple choice. Can you find the sequence, the ...
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6answers
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Through which number we can remove the question mark?

I'm trying to solve this puzzle but so much confused and can't understand even.Please help me to solve this puzzle and also explain briefly.
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1answer
888 views

Unable to solve a question asking to find the missing number in sequence

I am trying some quantitative aptitude questions and I am unable to solve this particular question: Unfortunately, I have no clue how it can be solved; I am not able to start. However, I know the ...
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What should the missing number be?

What number should be put instead of '?'? 9 4 3 3 26 8 6 22 28 ? 7 21
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Number Series - 1,20,171

$1,20,171,?,9625,57756,288775$ Please find the missing number in the series. I have already tried with squares, cubes and progressions but couldn't find the problem.
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399 views

What are the missing 7 numbers?

Below a sequence of numbers is stated, I'm looking for the 7 missing natural numbers which should replace the 7 x's. Counting will give you information which can be neither positive nor negative. ...
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Next number in the sequence 19, 10, 11, 18 ,38,?

What is the next number in the sequence 19, 10, 11, 18, 38,? The options are 97.5 110 115 124.5 99.5 I got an image from a book that had this question. I can't solve it. Any hints? Question ...
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Triangle puzzle

Can you guess the pattern? Fill in the blank for the last triangle
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597 views

Number sequence solving strategies

Number sequences are one of the oldest puzzle categories in the book. You would find it hard to look through a days worth of puzzles posted here and to not find any puzzles that involve some sort of ...
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399 views

Can you identify this function?

Can you identify the function depicted below? Edit: this is actually a function over nonnegative integers with the points interpolated by straight lines. I hope this helps.
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1answer
201 views

Board of Important Numbers

I was visiting my cousin, a mystery writer and lover of puzzles, when I noticed this list of numbers on her white board. 13,814,070 26,818,110 86,811,060 18,819,190 10,914,190 33,915,010 36,912,211 ...
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941 views

What is the next number to appear in this sequence?

$1, 1, 0, -2, 4, 18, 328, 107638 ,?$ This problem can be complex, use your imagination. Hint: Hint 2: Hint 3: Hint 4: Hint 5: Hint 6: Hint 7:
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958 views

Four blocks of numbers

A short number-riddle for warm-up: There are 4 blocks with 5 numbers each. Which one fits in the place of the "?"? ...
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478 views

Bitwise multiplication

Mr. EG has come up with a great coding scheme for (non-negative) integers in binary. To show off his creation, he demonstrates the following multiplications: ...
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Figure out this algorithm by analyzing the sequence of numbers generated

You are given a function f that, using an algorithm (that uses an old method), performs a calculation on four distinct values _ and generates a sequence of ten numbers. Now, your task is to figure ...
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1answer
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Find the missing number

What number should replace the ?
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544 views

Can you fill in the gaps in this number sequence?

The number sequence is 73, 70, 49, 52, 35, ?, ?, ?, ?, ?, 72,..... Can you fill in the gaps and predict what happens after 72? I have updated the hints below. ...
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1answer
425 views

What happened to the Fibonacci sequence?

I'm sure you've seen some of these numbers before: 1 3 8 13 21 30 36 45 54 63 Whats the next number in the sequence? And what have I done to the Fibonacci ...
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1answer
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Messages I sent

"The number of messages I sent yesterday was less than the messages I sent three days ago, and more than the messages I sent ten days ago." How many consecutive days can someone make this statement ...
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215 views

Find the replacement for `?`

624 --> 20 532 --> 117 634 --> 152 723 --> 40 443 --> 175 825 --> ? What should be filled in the last place so as to maintain the ...
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1answer
262 views

Unlucky thirteen

These two separate sequences use the same rule and stop at the 13th term. 2, 1, 8, 5, 2, 5, 8, 6, 7, 9, 7, 7, 0 3, 1, 5, 3, 9, 2, 4, 3, 9, 7, 3, 1, 0 These examples are produced when the ...
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380 views

Four indeed is cosmic!

This puzzle deals with positive integers in decimal representation. From every integer you can move to one or two or three other integers. The allowed moves for integer $n\ge1$ are as follows: You ...
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1answer
456 views

Matrix sequence

While a one-dimensional sequence is represented by a list, a two-dimensional sequence (a sequence of sequences) can be represented by a matrix. Find the pattern behind the following sequence, where a ...
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1answer
170 views

It's getting harder and harder for my friends to like me

What is the next number in this sequence? 2, 3, 6, 7, 9, 18, 25, 27, 54, 73, 97, 129, 171, 231, 313, 327, 649, 703, ... ? Hint 1 Hint 2 This is my first puzzle and I'm new to PSE, so feedback is ...
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537 views

A purely numerical sequence with a hint of the visual

What is the missing number in this cyclic sequence? It would require a notation convention not seen here to fit into the scheme here. $$\phantom{ \textrm{(repeat)} } \quad\textbf{?}~~ \,,~~ 2.4 \,,~~...
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1answer
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Prisoner Released If ? ??

One day a prison guard noticed a series of numbers scratched on the wall of an inmate's cell. Concerned it was something to do with an escape plan, the inmate was immediately questioned. 0-2-0-4-0-0-0-...
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1answer
420 views

Number sequence puzzle; 2, 10, 44 (+2 hints)

Predict the next three members of the sequence below and explain what the relationship is. 2, 10, 44, 1012, 248, This number sequence does not appear in the Online Encyclopedia of Integer Sequences ...
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1answer
318 views

Fill The grid - 3.0

Can you fill this grid ? Version ($\pi$) In text: ?14516 243748 120581 17186? 01?857 HINT 1 HINT 2 HINT 3
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195 views

Find the right triangle number

Here is my first try at a puzzle. Find the missing number. ...
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1answer
356 views

Encrypted growing sequence

The following sequence has been encrypted: 1-0 3-0 6-1 ...
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273 views

Sequence Puzzle - First Question of 42

Professor Tera was walking on Connecticut Road, where there are some public restrooms. Tera saw some students standing in a row. They seemed to be playing a game called Evolution. And it looked like ...

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