10 questions linked to/from Is this number triangular?
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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 ...
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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 ...
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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 ...
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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: ...
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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 ...
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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 ...
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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: ...
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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: ...
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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 ...
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