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 A215793 #7 Jul 22 2025 23:25:06 %S A215793 1,1,1,8,125,2988,146205,6812794,673507749,48337803306 %N A215793 Number of permutations of 0..floor((7*n-1)/2) on even squares of an 7*n array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing. %C A215793 Row 7 of A215788 %e A215793 Some solutions for n=4 %e A215793 ..0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x %e A215793 ..x..2..x..4....x..2..x..3....x..2..x..3....x..2..x..4....x..2..x..4 %e A215793 ..3..x..5..x....4..x..5..x....4..x..5..x....3..x..5..x....3..x..5..x %e A215793 ..x..6..x..7....x..6..x..7....x..6..x..7....x..6..x..8....x..6..x..8 %e A215793 ..8..x..9..x....8..x..9..x....8..x..9..x....7..x..9..x....7..x..9..x %e A215793 ..x.10..x.12....x.10..x.12....x.10..x.11....x.10..x.12....x.10..x.11 %e A215793 .11..x.13..x...11..x.13..x...12..x.13..x...11..x.13..x...12..x.13..x %K A215793 nonn %O A215793 1,4 %A A215793 _R. H. Hardin_ Aug 23 2012