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 A264691 #3 Nov 21 2015 07:30:17 %S A264691 1,7,80,2051,59845,3406328,233531136,21272671232 %N A264691 Number of nX3 arrays of permutations of 0..n*3-1 with rows nondecreasing modulo 3 and columns nondecreasing modulo 5. %C A264691 Column 3 of A264692. %e A264691 Some solutions for n=5 %e A264691 .10..1..5....0..1.10....6.12..0....0..6..5....0.10..7....7.10..5....5.11..2 %e A264691 ..0..7.11....6.12..5....8..2..5...10..1..7...11..5..2...12..0..6....0.12..3 %e A264691 ..6.12..2...13..7.11...13..7.10...12.11..2...12..1.13....3..1..2...10..7.13 %e A264691 ..3..8.14....3..8..2....3..9..1....4.13..8....9..6..3....8.11.14....6..9..8 %e A264691 ..9.13..4....9..4.14....4.14.11....9..3.14....4..8.14....9.13..4....1..4.14 %Y A264691 Cf. A264692. %K A264691 nonn %O A264691 1,2 %A A264691 _R. H. Hardin_, Nov 21 2015