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 A264421 #3 Nov 12 2015 23:00:42 %S A264421 0,385,15088,1103666,95946259,7577203142,577598946184,44052069039720 %N A264421 Number of (n+1)X(6+1) arrays of permutations of 0..n*7+6 with each element having directed index change 0,1 2,2 1,0 -1,2 -2,-1 or -1,-1. %C A264421 Column 6 of A264422. %e A264421 Some solutions for n=3 %e A264421 .15..9..7..2.12..4..5....8..9.10.11.12..4..5....8..9..1.18.12..4..5 %e A264421 ..0..1.17..3.19.20..6....0.16.24..3.19.20..6....0.16..2..3.19.20..6 %e A264421 .22..8.24.25.11.27.13....7.23.21..1..2.27.13....7.23.21.25.11.27.13 %e A264421 .14.21.16.23.18.10.26...14.15.22.17.18.25.26...14.15.22.17.24.10.26 %Y A264421 Cf. A264422. %K A264421 nonn %O A264421 1,2 %A A264421 _R. H. Hardin_, Nov 12 2015