# Questions tagged [number-sequence]

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

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### What is this magic trick with 6 cards featuring numbers between 1 and 60?

I hope this is on topic. I have a set of kids' magic tricks but I have lost the instructions! I was hoping this might be a good place to get some help. Here is the first one. What is the trick and ...
2k views

### 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 ...
50k views

### Fill the holes? [closed]

You have to fill the boxes to make the equation true:   +   +   = 30 Using only 1, 3, 5, 7, 9, 11, 13, 15. You can also repeat the numbers. (eg: 1 + 1 + 1) Edit1: the boxes of the equation are ...
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### A tricky batch of four number sequences

What are the next few numbers in each of these integer sequences? Each of them has a clear and justifiable solution. 1, 2, 3, 5, 8, 9, 12, 20, 21, 22, ??, ??, ... 50, 49, 48, 46, 45, 44, 43, ...
861 views

### Lalozik Pattern

Vasily Lalozik is a professional cryptographer and develops new security schemes for banks. But he has one problem: David Banes. The American Bank is the largest bank in the world; Banes has his ...
667 views

### Sorcery squares!

The following 5-by-5 squares of digits are not magic squares, but nevertheless they each have a crucial property which enabled me to generate them. What is that property? How could you generate more ...
3k views

### Ancient machine in the desert… how does it generate its output?

I was walking through the desert and came across an ancient contraption of cogs and gears. It had a series of dials on one side that appeared to allow the input and output of numbers. On the other ...
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 ...
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### 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 ...
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. ...
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### 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 ...
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,...
206 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 ...
384 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, ...
780 views

### From a math Professor, Bernard Budiansky

What is next in the sequence? 50, 42, 34, 28, 23, 18,14, ?
653 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 ...
301 views

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### 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.
9k 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