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 A223717 #7 Jul 23 2025 04:25:31 %S A223717 3,81,5883,608855,74140718,9991366555,1461411174370,229731305080429, %T A223717 38440119395606004 %N A223717 Number of n X n 0..2 arrays with rows, antidiagonals and columns unimodal. %C A223717 Diagonal of A223725 %e A223717 Some solutions for n=3 %e A223717 ..2..1..1....2..2..0....2..2..2....1..1..2....2..0..0....2..1..1....1..2..1 %e A223717 ..0..0..1....2..1..1....2..2..0....2..1..1....0..1..0....1..2..2....1..2..1 %e A223717 ..0..0..0....1..1..1....2..2..0....0..0..1....0..2..0....0..1..0....0..1..0 %K A223717 nonn %O A223717 1,1 %A A223717 _R. H. Hardin_ Mar 26 2013