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 A264358 #4 Nov 12 2015 06:56:00 %S A264358 1,6,169,7168,831744,353333680,450847788304,1591640798421348 %N A264358 Number of (n+1)X(n+1) arrays of permutations of 0..(n+1)^2-1 with each element having directed index change 0,0 0,2 1,0 or -1,-2. %C A264358 Diagonal of A264364. %e A264358 Some solutions for n=4 %e A264358 ..7..8..9..1..2....0..8..9..3..4....0..8..9..1..4....0..1..9..3..4 %e A264358 ..0..6..5..3..4...12..1..2..6..7....5..6..2..3..7....5..6..2..8..7 %e A264358 .17.11.10.13.12....5.18.19.11.14...17.11.10.13.12...17.18.10.11.14 %e A264358 .15.16.24.18.14...10.16.15.13.17...15.23.24.18.14...22.16.12.13.19 %e A264358 .20.21.22.23.19...20.21.22.23.24...20.16.22.21.19...15.21.20.23.24 %Y A264358 Cf. A264364. %K A264358 nonn %O A264358 1,2 %A A264358 _R. H. Hardin_, Nov 12 2015