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 A223891 #6 Jul 23 2025 04:38:25 %S A223891 46,3298,187103,8878492,367772497,13710418065,469842794992, %T A223891 15032271992980,454296896353698,13086457136814204,361878926424024255, %U A223891 9661547783502821964,250204578633128649051,6309270603849297385833 %N A223891 Number of nX4 0..2 arrays with row sums and column sums unimodal. %C A223891 Column 4 of A223892 %H A223891 R. H. Hardin, <a href="/A223891/b223891.txt">Table of n, a(n) for n = 1..15</a> %e A223891 Some solutions for n=3 %e A223891 ..0..1..2..0....0..2..2..2....0..1..0..2....0..1..0..1....0..1..1..2 %e A223891 ..2..0..1..1....0..0..1..1....1..2..2..2....1..1..2..0....2..2..2..2 %e A223891 ..0..1..2..1....0..0..0..0....0..0..2..1....0..1..2..0....1..0..1..0 %K A223891 nonn %O A223891 1,1 %A A223891 _R. H. Hardin_ Mar 28 2013