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 A215792 #7 Jul 22 2025 23:24:59 %S A215792 1,1,1,4,50,458,15485,234217,14296434,297246092,26970790176 %N A215792 Number of permutations of 0..floor((6*n-1)/2) on even squares of an 6*n array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing. %C A215792 Row 6 of A215788 %e A215792 Some solutions for n=5 %e A215792 ..0..x..1..x..4....0..x..1..x..2....0..x..1..x..4....0..x..1..x..2 %e A215792 ..x..2..x..5..x....x..3..x..4..x....x..2..x..5..x....x..3..x..4..x %e A215792 ..3..x..6..x..8....5..x..6..x..7....3..x..6..x..8....5..x..6..x..8 %e A215792 ..x..7..x.10..x....x..8..x..9..x....x..7..x..9..x....x..7..x..9..x %e A215792 ..9..x.11..x.13...10..x.11..x.13...10..x.11..x.13...10..x.11..x.12 %e A215792 ..x.12..x.14..x....x.12..x.14..x....x.12..x.14..x....x.13..x.14..x %K A215792 nonn %O A215792 1,4 %A A215792 _R. H. Hardin_ Aug 23 2012