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 A264559 #3 Nov 17 2015 18:04:49 %S A264559 2,24,888,58368,7019136,1202698368 %N A264559 Number of nX3 arrays of permutations of 0..n*3-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 3. %C A264559 Column 3 of A264560. %e A264559 Some solutions for n=4 %e A264559 ..0..6..3....9..1..3...10..6..3....6..0..3....9..7..3....3.11..9....6..0.10 %e A264559 .10..4..9....0..4..2....7..9..1....1..5..9....0..4..6....6..8..0....3..9..7 %e A264559 ..1..7..5....6..7.11....4..0..5....4..8..7...10..2..8....7..5..1....5.11..1 %e A264559 ..2..8.11...10..8..5....8..2.11...10..2.11....1..5.11...10..2..4....8..2..4 %Y A264559 Cf. A264560. %K A264559 nonn %O A264559 1,1 %A A264559 _R. H. Hardin_, Nov 17 2015