# 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 ...

### 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. ...

### 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 ...

### Catalan Numbers

C, 78 52 39 34 33 bytes Even more C magic (thanks xsot): c(n){return!n?:(4+6./~n)*c(n-1);} ?: is a GNU extension. This time by ...

### 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 ...

### Bernoulli Numbers

Mathematica, 40 28 23 22 bytes Using the famous formula n*ζ(1−n)=−Bn, where ζ is the Riemann Zeta function. If[#>0,-Zeta[1-#]#,1]& The same length: <...

### Catalan Numbers

Jelly, 4 bytes Ḥc÷‘ Try it online! How it works ...

### 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 ...

### Counting universal n-ary logic gates

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

### Compute the multinomial coefficient

Jelly, 7 6 bytes ;_/!:/ Look ma, no Unicode! This program takes a single list as input, with n at its first index. Try it online! or verify all test cases at ...

### Count sums of two squares

Python (59 57 56 bytes) lambda n:0**n+sum((-(n%(x-~x)<1))**x*4for x in range(n)) Online demo As with my CJam answer, this uses Möbius inversion and runs in ...

### Deranged !Combinatorics: Compute the Subfactorial

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

### 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 ...

### Stuffing primes in a box

Smalltalk, 1098 primes First off, nice hard question - as evidenced by the lack of non-trivial responses thus far. I had a solution cooking at work, but had to wait for the long weekend to have time ...

### 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] -> ...

### Converge to a number

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

### 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 ...

### Code-Golf: Permutations

Python, 52 Input is a set. Output is a list of lists. f=lambda a:[p+[x]for x in a for p in f(a-{x})]or[[]] This is shorter than the answer that does all the work ...
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 ...

### Count sums of two squares

Python 2, 44 bytes f=lambda n,x=1:+(x>n)or(n%x<1)-f(n,x+2)/4<<2 This is almost the same as xsot's solution (which is based on Peter Taylor's solution)...

### 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! ...

### 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 ...
Accepted

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

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