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 A264470 #6 Sep 07 2022 16:06:58 %S A264470 0,2,6,120,3540,310748,74367790,44706530288,66581992940380, %T A264470 252580385620049120 %N A264470 Number of (n+1) X (n+1) arrays of permutations of 0..(n+1)^2-1 with each element having directed index change 0,1 1,0 2,1 or -1,-1. %C A264470 Diagonal of A264476. %e A264470 Some solutions for n=4 %e A264470 ..6..0..8..9..3....6..0..1..2..3....6..7..1..9..3....6..0..8..9..3 %e A264470 .11..1..2.14..4...11..5.13.14..4....0..5..2.14..4...11..5..2..7..4 %e A264470 .16.10..7.19.13...16.17..7..8..9...16.17.11..8.13...16.10..1.12.13 %e A264470 .21..5.12.24.18...10.22.23.24.18...10.22.23.24.18...21.22.23.24.14 %e A264470 .15.20.17.22.23...15.20.21.12.19...15.20.21.12.19...15.20.17.18.19 %Y A264470 Cf. A264476. %K A264470 nonn %O A264470 1,2 %A A264470 _R. H. Hardin_, Nov 14 2015