Questions tagged [number-sequence]

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

Filter by
Sorted by
Tagged with
2
votes
1answer
7k views

Math Number Sequence Riddle with 4 numbers 8 digits [duplicate]

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So it can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits, the threes ...
4
votes
3answers
976 views

A simple but most devious sequence puzzle

This is a question from a previous, now-defunct version of the Temple of Quetzalcoatl, that I've posted here as an exemplar of one of the difficult puzzles you might encounter while solving it. The ...
12
votes
3answers
2k views

Three different, and somewhat difficult, sequence puzzles

Here are three different letter/number sequences. Try to solve as many as possible. The spoilers give hints to each sequence in the form of how many elements are in the corresponding sequence. ...
9
votes
5answers
2k views

Another one of those odd sequence puzzles

This is an interesting one. I will do the same thing that I usually do. After one week, a hint. After 2 weeks, a hint. After 3 weeks, an answer. I may change this system. What number goes in the ...
8
votes
2answers
2k views

What is the next term in the sequence?

The first term is f(0), the last term is f(2000): 0,0,0,0,1,0,1,0,2,1,1,0,2,0,1,1,3,0,2,0,2,1,1,0,3,1,1,2,2,0,2,0,4,1,1,1,3,0,1,1,5,0,2,0,2,2,1,0,4,1,2,1,2,0,3,1,5,1,1,0,3,0,1,2,6,1,2,0,2,1,2,0,4,0,1,...
7
votes
1answer
181 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 ...
0
votes
1answer
377 views

A final batch of four sequence puzzles

This is my seventh (and probably last) batch of sequence puzzles that are nasty and hard to solve; I stress that each of them has a clear and justifiable solution. Sequence 1: RC, NU, RT, RS, PI, ...
1
vote
2answers
780 views

From a math Professor, Bernard Budiansky

What is next in the sequence? 50, 42, 34, 28, 23, 18,14, ?
1
vote
3answers
639 views

A benevolent but cumbersome batch of four sequence puzzles

Here are four more sequence puzzles. The challenge is to guess the pattern and hence fill in the missing terms. Each "???" denotes exactly one missing term. 6, ???, 5, 8, 4, ???, 7, 3, 4, ???, 4 (now ...
8
votes
2answers
288 views

Which are the missing dates?

Here are the dates for a series of events. As you can see, some of the dates are missing. What are the missing dates. And what happened at these dates? $~~~????,~ 1914,~ ????,~ 1939,~ 1958,~ ????,~...
4
votes
2answers
252 views

Yet another batch of four sequence puzzles

This is my sixth batch of sequence puzzles that are nasty and hard to solve; yet, each of them has a clear and justifiable solution. Sequence 1: Ca, Cl, ??, Er, ??, Po, Te, Th, ?? Sequence ...
5
votes
1answer
283 views

A Prime Example of a Number Pattern

Can you fill in the holes in this pattern? 361 722 726 [A] 323 650 223 49729 99458 [B] 19024 2538 2240 98 102 302 22805 [C] EDIT: As the answer has been found, ...
3
votes
2answers
237 views

The Common Thread

What common property unites all of the following numbers? 4, 9, 60, 101, 400, 450, 910, 1010 The set of numbers that share this common property is not limited to just these eight, but the list ...
16
votes
5answers
2k views

Should the angels play their game?

Two angels in heaven want to play a game. One of them comes up with an arbitrary, computable function from the integers to the integers. The other angel has to guess what it is. The second angel can ...
5
votes
2answers
967 views

Is there a logic to this sequence?

Got this as a question in an IQ test and cannot figure it out. Does anyone know? 12, 26, 31, 76, 77, 94, 101.
6
votes
1answer
1k views

Find the missing number

What number should replace the ?
2
votes
3answers
287 views

One more batch of four sequence puzzles

This is my fifth batch of sequence puzzles that are nasty and hard to solve; yet, each of them has a clear and justifiable solution. Sequence 1: T?M, AOT?, ROT?, AN?, T?SB, ROT?, TFA Sequence ...
-4
votes
3answers
215 views

A rectangle of numbers

Six numerals and two ? symbols are arranged in a $2\times4$ rectangle. ? ? 8 9 5 6 2 3 Apparently, either one or two different symbols are needed to replace the ...
8
votes
1answer
1k views

What is the next number in the sequence?

What is the next number in the following sequence? 9999999, 4782969, 217728, 1568, ??? I saw this question in an app and I am stuck. Can you help me? Source: https://play.google.com/store/apps/...
0
votes
3answers
344 views

A batch of four sequence puzzles

This is my fourth batch of sequence puzzles that are nasty and hard to solve; yet, each of them has a clear and justifiable solution. Sequence 1: 2, ?, ?, ?, 0, 3, 7, 6, 4, 6, 9, 0, ?, 0, 4, 3, ...
5
votes
4answers
296 views

Yet another group of five sequence puzzles

This is my third batch of sequence puzzles that are nasty and hard to solve; yet, each of them has a clear and justifiable solution. Sequence 1: 2, 4, 4, 3, ?, ?, 3, 4, 2, 4, 3, 4, 2, 2, 3, 4, 4,...
2
votes
5answers
839 views

Five further sequence puzzles

This is my second batch of sequence puzzles that are nasty and hard to solve; yet, each of them has a clear and justifiable solution. Sequence 1: 18, 17, 18, 22, 26, 35, 32, 32, ??, 38, ??, 52, ?...
10
votes
4answers
1k views

Five sequence puzzles

The following five sequence puzzles are quite nasty and hard to solve. Yet, each of them has a clear and justifiable solution. Sequence 1: ?, ?, ?, B, B, C, ?, ?, F, ?, S, M, A, S, P, S, C, A, .....
22
votes
1answer
4k views

Very simple, yet unsolved, sequence of numbers

A simple sequence of numbers, which I encountered during intermediate school, in my math book. Any person that finished intermediate school possesses the necessary toolbox required to solve this ...
3
votes
2answers
2k views

whats the Missing Number?

In this grid of numbers, what is the missing number (in place of the question mark)? $$\begin{array}{|c|c|}\hline2&7\\\hline8&9\\\hline\end{array} \begin{array}{|c|c|}\hline0&3\\\hline5&...
2
votes
1answer
1k views

What is the next number in this sequence?

Can you determine the next number in the below sequence? $1.0 , 4.0 , 6.9 , 9.0 , 10.8 , 12.0 , 14.0 , 16.0 , ?$ Bonus: Determine the next number that comes after '?' Note: I'll post some hints if ...
6
votes
2answers
2k views

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.
1
vote
2answers
3k views

What is the next number? 24,54,90,120,168,210,240,288,360,440 [closed]

Question : What is the next number in the following sequence? (not finite) $$\large24,54,90,120,168,210,240,288,360,440,\dots$$ My Solution I'm trying a closed form solution I tried computing ...
10
votes
2answers
2k views

What is the next number in this sequence? 0, 1, 11.2, 10.2, 113.2, 103, 103.2, 0.2, 1.2, 2.2, 2, …

0, 1, 11.2, 10.2, 113.2, 103, 103.2, 0.2, 1.2, 2.2, 2, ? The only hint I'll give at this stage is that the sequence is infinite. If nobody gets it within a few days, I'll give a few terms that come ...
12
votes
5answers
2k views

Sequence Brain Teaser: Fill the gaps to create arithmetic sequences

Fill in each blank unshaded cell in the diagram below with a positive integer less than 100, such that every consecutive group of unshaded cells within a row or column is an arithmetic sequence. This ...
7
votes
1answer
1k views

Oh no! Yet another number series… - Find the pattern in the two examples and provide an extension

Because these have been so successful in the past, I had to bring up my own. In fact, this puzzle was inspired by Find the next number even though I (and I guess everybody but the author) still don't ...
5
votes
2answers
439 views

Continue this number-triplet series

(4-6-4) (6-12-8) (8-12-6) (12-30-20) What is the next number triplet - and why? I'll add hints if nobody gets the answer first. In the past I've used this riddle in a game with my RPG gaming group. ...
3
votes
1answer
1k views

Missing number in this sequence?

I heard this puzzle in a quiz I participated in: 10, 11, 12, 13, 14, 15, 16, 17, 20, 22, 24, ?, 100, 121, 10000 What is the missing number? (You don't need to do any big calculations, and you ...
6
votes
2answers
533 views

Determine what the last number in this series is

4, 23, 20, 12, 14, 9, 20, 19, ? Also explain your reasoning.
12
votes
5answers
1k views

Are you a Detective

A detective friend of yours was trying to find clues for a crime he was investigating, he was almost done but a concluding location will help you close the case. Unfortunately your friend could only ...
-3
votes
1answer
466 views

Finish The Pattern

Please note I realize there could be many "correct answers" but I'm looking for a specific one. 1, 3, 5, 4, 2, 7, 6, 8, 9, 3, 4, 5, 8, 2, 9, 3, 5, 2, 42, 35, 42, 52, 55, 52, 109, 85, 120, ?, ?, ? ...
-1
votes
2answers
2k views

Petals around the rose

You roll 5 dice and I'll always be able to give a number uniquely-defined by the numbers on the dice. You have to figure out how it works, without looking it up. Here's a couple example rolls: 1,2,3,...
6
votes
3answers
976 views

What is the next 3 numbers?

These numbers are created with a formula. Guess the formula for increment and calculate at least 3 next numbers of this sequence. increment is started with two given first $1$s. $1,$ $1,$ $2,$ ...
1
vote
2answers
1k views

What are the next 5 numbers in the sequence?

It's a simple pattern I thought of. Here it is: 1,1,1,3,3,6,6,10,10,22,22,44,44,84,?,?,?,?,? Whoever gives the correct answer and a good explanation gets best answer.
49
votes
4answers
8k views

Interview Question or Pathbreaking puzzle

I thought this changes the way series of numbers are looked at 1 1 1 2 1 1 2 1 1 Write down the next three lines
2
votes
1answer
2k views

Find the next number in the series?

Find the value of 'a' and 'b' in the following series. 100,101,120,103,410,321,205,404,60a,5b2
8
votes
1answer
546 views

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.