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 A223664 #7 Jul 23 2025 04:21:50 %S A223664 2,16,292,6454,136289,2715255,51831694,962697852,17643516790, %T A223664 323311474180 %N A223664 Number of n X n 0..1 arrays with rows, diagonals and antidiagonals unimodal. %C A223664 Diagonal of A223669 %e A223664 Some solutions for n=4 %e A223664 ..1..0..0..0....1..1..1..0....0..1..0..0....0..1..1..0....0..0..1..0 %e A223664 ..0..1..1..0....0..1..1..0....0..0..1..0....0..0..1..0....1..1..1..1 %e A223664 ..1..1..0..0....0..1..1..1....0..1..1..0....0..0..1..0....0..1..1..0 %e A223664 ..0..1..1..0....0..1..1..1....1..1..1..1....0..0..1..0....0..1..1..1 %K A223664 nonn %O A223664 1,1 %A A223664 _R. H. Hardin_ Mar 25 2013