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 A223813 #6 Jul 23 2025 04:33:26 %S A223813 46,1922,65465,1941904,52310070,1313561156,31302500115,716436867795, %T A223813 15887478421991,343524128791643,7277651757377395,151618311154271042, %U A223813 3115328781386015762,63276105450145436904,1272818850579941619368 %N A223813 Number of nX4 0..2 arrays with row sums nondecreasing and column sums unimodal. %C A223813 Column 4 of A223815 %H A223813 R. H. Hardin, <a href="/A223813/b223813.txt">Table of n, a(n) for n = 1..19</a> %e A223813 Some solutions for n=3 %e A223813 ..1..0..0..0....2..1..1..1....0..1..1..2....0..2..0..0....0..0..1..0 %e A223813 ..1..1..2..1....2..2..1..0....1..1..2..0....1..1..2..0....1..0..0..0 %e A223813 ..2..2..1..2....1..2..2..1....2..2..1..1....1..2..1..2....0..1..0..2 %K A223813 nonn %O A223813 1,1 %A A223813 _R. H. Hardin_ Mar 27 2013