This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A221437 #5 Jul 23 2025 01:55:46 %S A221437 5040,9344160,5411750400,782137036800,20449013760000,61479419904000, %T A221437 61479419904000 %N A221437 Number of nX7 1..(max n,7) arrays with each row and column having unrepeated values. %C A221437 Column 7 of A221438 %e A221437 Some solutions for n=2 %e A221437 ..1..2..3..4..5..6..7....1..3..5..2..6..4..7....1..2..3..4..7..6..5 %e A221437 ..2..7..1..3..6..4..5....2..5..6..4..3..7..1....2..4..6..1..5..3..7 %K A221437 nonn %O A221437 1,1 %A A221437 _R. H. Hardin_ Jan 16 2013