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 A223817 #6 Jul 23 2025 04:33:50 %S A223817 10,222,4120,65465,921010,11789302,139965348,1562685952,16583874090, %T A223817 168662333466,1654400665258,15732261029037,145639935220714, %U A223817 1317015705919726,11667008847929888,101490035584201884 %N A223817 Number of 3Xn 0..2 arrays with row sums nondecreasing and column sums unimodal. %C A223817 Row 3 of A223815 %H A223817 R. H. Hardin, <a href="/A223817/b223817.txt">Table of n, a(n) for n = 1..48</a> %e A223817 Some solutions for n=3 %e A223817 ..2..1..0....1..1..0....0..2..1....1..2..0....0..1..1....0..0..0....0..2..1 %e A223817 ..2..0..2....2..1..2....0..1..2....1..2..0....1..2..0....2..1..0....0..2..1 %e A223817 ..1..2..1....2..2..2....2..0..2....1..1..2....1..2..1....2..1..2....0..2..2 %K A223817 nonn %O A223817 1,1 %A A223817 _R. H. Hardin_ Mar 27 2013