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 A264661 #3 Nov 20 2015 07:28:08 %S A264661 1,8,314,20940,3084352,726042624,284038382592 %N A264661 Number of 3Xn arrays of permutations of 0..n*3-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 5. %C A264661 Row 3 of A264659. %e A264661 Some solutions for n=5 %e A264661 ..0..2.10..6..5....0.12..6..2.10....0.10..6..1..7....0.10..7..5..1 %e A264661 ..8..7.11..3..1....8..7.11.13..5....8..5.11..9.13....4..2.12..6.11 %e A264661 .14.12..4..9.13....4.14..1..9..3....4.12..2.14..3...14..8.13..9..3 %Y A264661 Cf. A264659. %K A264661 nonn %O A264661 1,2 %A A264661 _R. H. Hardin_, Nov 20 2015