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 A223816 #6 Jul 23 2025 04:33:44 %S A223816 6,50,337,1922,9783,45537,198252,817482,3229096,12308970,45575437, %T A223816 164673074,582981253,2028408899,6954637113,23545924195,78860147938, %U A223816 261655333573,861137618468,2814055941811,9138890924393,29517256515379 %N A223816 Number of 2Xn 0..2 arrays with row sums nondecreasing and column sums unimodal. %C A223816 Row 2 of A223815 %H A223816 R. H. Hardin, <a href="/A223816/b223816.txt">Table of n, a(n) for n = 1..143</a> %e A223816 Some solutions for n=3 %e A223816 ..0..0..1....0..2..1....1..1..0....1..2..1....1..1..0....0..0..0....0..1..1 %e A223816 ..0..0..1....0..2..2....1..1..0....1..1..2....2..1..0....0..1..0....2..2..2 %K A223816 nonn %O A223816 1,1 %A A223816 _R. H. Hardin_ Mar 27 2013