# Tag Info

### Absolute Sums of Sidi Polynomial Coefficients

Python 2, 43 bytes f=lambda n,k=1:k/n or n*f(n,k+1)+k*f(n-1,k) Try it online! A different approach Ever since I posted this challenge, I tried to come up with a ...
• 210k

### Anaglot Polygrams

34 Languages, 19 bytes, Score: 38,832,018,459,912,437,760,000 Here is a quick answer I threw together to show that it is possible to get an answer scoring better than 1. ...
• 98.9k

### Every word from babab to zyzyz

Mathematica, 72 65 61 bytes Print@@@Tuples@{a=##/(b=#5#9#15#21#25#)&@@Alphabet[],b,a,b,a} For testing, I recommend replacing ...
• 197k

### Concentric rings on a snub square tiling

Ruby, 26 bytes ->n{~-n*12-496/4**n%4+1/n} Try it online! Revised version adding 1/n and subtracting ...
• 26.3k

### The square root of the square root of the square root of the…

APL (Dyalog Unicode), 39 bytes +/⊢{∨/⍺⍵<⍵0:0⋄⍺=0:1⋄+/∊∇¨/⍺(⍵*2)-⊂⍳⍺}¨⍳ Try it online! A tacit function containing an inner dfn to use recursion. Does not use ...
• 77.2k

• 6,276

### Counting universal n-ary logic gates

Python 3.8 (pre-release), 287 282 242 bytes -5 bytes thanks to @Dialfrost ...
• 7,898

### Brute-force the switchboard

Haskell, 25 24 23 17 bytes mapM\$min"^v".pure Try it online! -1 byte thanks to @H.PWiz -1 byte thanks to @nimi Returns a list of strings. The TIO has 2 extra ...
• 4,006

### Don't repeat yourself in Rock-Paper-Scissors

Ruby, 39 bytes ->n{(?P*n..?S*n).grep_v /[^RPS]|(.+)\1/} This hilariously inefficient function generates all strings of length N that lie alphabetically ...
• 22.2k

### Deranged !Combinatorics: Compute the Subfactorial

Funciton, 336 bytes Byte count assumes UTF-16 encoding with BOM. ...
• 197k

### Partitioning the grid into triangles

Haskell, 60 55 54 52 bytes After a drawing and programming a lot of examples, it occured to me that this is the same as the problem of the rooks: On a $(n+1) \times (n+1)$ chessboard, how many ...
• 43.8k

### A penny saved is a penny

Haskell, 37 34 bytes s#l@(c:d)|s>=c=(s-c)#l+s#d s#_=0^s Usage example: 26 # [1,5,10,25] -> ...
• 35.9k

### Converge to a number

Jelly, 9 bytes DLḶU⁵*xDÄ Try it online! ...
• 68.8k

### Enumerate all pure sets

Python, 43 bytes f=lambda x:[f(i)for i in range(x)if x>>i&1] Attempt This Online! Outputs the $n$th set, starting at $0$. One way of creating a sequence of all pure sets is to encode ...
• 23.9k
Accepted

### Generate all combinations of given list of elements, sorted

Jelly, 1 byte TryItOnline Cartesian power built-in atom, as a dyadic link with left argument the items and right argument the count, or as a full program with ...
• 108k

### Super permutations

Scratch 3.0, 65 blocks / 637 632 bytes Look at y'all, having fun with your fancy shmancy permutation functions/map tools. Well, not I! No, not I! When using Scratch, one has to do things themselves! ...
• 33.7k

### Never trust a mastermind

JavaScript (ES6),  116 112  107 bytes Expects an array of entries in the following format: [[a,b,c,d], "XY"], where a ...
• 194k
Accepted

### Cut a triangle into equal-sized parts!

JavaScript (ES7),  367 362 359  357 bytes Saved 1 byte thanks to @Shaggy Expects (n)(m). ...
• 194k

### Just Enough Ones

J, 41 bytes 1#.*:=1#.2>[:>@~.@,[:+&,&.>/~i.@!<@A.=@i. Try it online! A different take on brute force, which handles up to n=6 on TIO. Since the ...
• 33.6k

### A penny saved is a penny

Mathematica, 35 22 bytes Thanks to miles for suggesting FrobeniusSolve and saving 13 bytes. Length@*FrobeniusSolve Evaluates ...
• 197k

### Arranging Bubbles

Python 2, 92 87 bytes a=lambda n:n<2or sum((k%d<1)*d*a(d)*a(n-k)for k in range(1,n)for d in range(1,1+k))/~-n In plain english: to compute ...
• 39.1k

### Largest monetary amount impossible to make with two types of coin

J, 7,6 3 bytes -1 byte thanks to FrownyFrog ! -3 bytes thanks to Grimmy! *-+ Try it online! ...
• 21k

### Every word from babab to zyzyz

Perl, 47 bytes #!perl -l /((^|[aeiouy])[^aeiouy]){3}/&&print for a..1x5 Counting the shebang as one. Try it online!
• 33.3k

### Permutations in Disguise

Python 2, 60 bytes def f(l):z=zip(l,range(len(l)));print map(sorted(z).index,z) Try it online! Uses zero-indexing. A fast algorithm with a simple idea. If we ...
• 145k

### Number of distinct tilings of an n X n square with free n-polyominoes

C, 7 terms The seventh term is 19846102. (The first six are 1, 1, 2, 22, 515, 56734, as stated in the question). ...
• 15.8k

### Triangular domino tiling of an almost regular hexagon

APL (Dyalog Classic), 14 bytes ×/1+1÷1+∘,1⊥¨⍳ Try it online! Uses 0 indexing with ⎕IO←0. Explanation: ...
• 47.3k

Python 3.8, 81, 79, 75 bytes Using the walrus operator :=: ...
• 671
Python 2, 66 59 bytes lambda n,k:sum(a%n*(n-a%n)==a/n*(k-a/n)for a in range(n*k)) Try it online! Each possible rectangle inside the $n \times k$-rectangle can ...