Linked Questions
10 questions linked to/from Is this number triangular?
85
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Sum of all integers from 1 to n
I'm honestly surprised that this hasn't been done already. If you can find an existing thread, by all means mark this as a duplicate or let me know.
Input
Your input is in the form of any positive ...
- 1,299
50
votes
92
answers
8k
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Is this number a factorial?
The Task
Given a natural number as input, your task is to output a truthy or falsey value based on whether the input is a factorial of any natural number. You can assume that the input number will ...
- 5,084
52
votes
81
answers
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It's Hip to be Square
Challenge
So, um, it seems that, while we have plenty of challenges that work with square numbers or numbers of other shapes, we don't have one that simply asks:
Given an integer ...
- 43.5k
49
votes
71
answers
7k
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An abundance of integers!
An Abundant number is any number where the sum of its proper divisors is greater than the original number. For example, the proper divisors of 12 are:
...
- 59.6k
62
votes
44
answers
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Find the Smoothest Number
Your challenge is to find the smoothest number over a given range. In other words, find the number whose greatest prime factor is the smallest.
A smooth number is one whose largest prime factor is ...
- 42.1k
20
votes
31
answers
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Is this number tetrahedral?
Happy New Year 2024!
2024 is a tetrahedral number. A tetrahedral number is a number that can be represented in the form \$n(n+1)(n+2)/6\$ for some positive integer \$n\$. Or, equivalently, they are ...
- 50k
33
votes
7
answers
6k
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Match strings whose length is a fourth power
Within the scope of this question, let us consider only strings which consist of the character x repeated arbitrary number of times.
For example:
...
11
votes
17
answers
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Triangle and/or Square? [duplicate]
Explanation of the challenge
Given an input, return what shapes it could be. There are only a couple options.
Square
Triangle
Square
A square is in the following format:
...
- 2,535
16
votes
8
answers
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Decompose a number into triangles
Given an integer n, decompose it into a sum of maximal triangular numbers (where Tm represents the mth triangular number, or the sum of the integers from 1 to m) as follows:
while n > 0,
find the ...
- 71.7k
12
votes
9
answers
1k
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Polygonal Numbers!
Introduction
In mathematics, a polygonal number is a number represented as dots or pebbles arranged in the shape of a regular polygon. The dots are thought of as alphas (units). These are one type ...
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