12 questions linked to/from Upgoat or Downgoat?
12k views

### Create an “H” from smaller “H”s

Challenge Create a function or program that, when given an integer size, does the following: If size is equal to 1, output <...
4k views

### Output the Arecibo Message

The Arecibo message is a 1974 interstellar radio message carrying basic information about humanity and Earth sent to globular star cluster M13 in the hope that extraterrestrial intelligence might ...
7k views

### Print the Russian Cyrillic alphabet [duplicate]

Apparently, we really like printing the alphabet in different languages. How about the Russian Cyrillic alphabet? Print/output/return this exact text (trailing whitespace is permitted) ...
7k views

### Convert singular to plural

There are two forms of nouns, singular and plural. The conversion between these two is quite easy. Normally, you end it with s. ex. ...
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### Output the Euler Numbers

Given a non-negative integer $n ,$ output the $n^{\text{th}}$ Euler number (OEIS A122045). All odd-indexed Euler numbers are $0 .$ The even-indexed Euler numbers can be computed with the ...
4k views

Challenge Given an IPv4 address in dotted-quad notation, and an IPv4 subnet in CIDR notation, determine if the ...
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### The qvolume of an integer

It is ancient knowledge that every non-negative integer can be rewritten as the sum of four squared integers. For example the number 1 can be expressed as $0^2+0^2+0^2+1^2$. Or, in general, for any ...
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### Is it within the Cantor set?

The Challenge For this challenge, you are supposed to determine if a given number is in the Cantor set. So first, let's define the Cantor set. First, start with the numbers between 0 and 1. Any ...
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### Prove me wrong!

Introduction Your mission in life is simple: Prove people wrong on the internet! To do this you usually carefully analyze their statements and point out the contradiction in them. It's time to ...
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### Where's Blackhat?

Challenge Write code which, given an image of a panel from a random xkcd comic, returns a truthy value if Blackhat is in the comic or falsey if not. Who is Blackhat? Blackhat is the unofficial name ...