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 A223675 #7 Jul 23 2025 04:22:51 %S A223675 2,16,316,9822,384009,17068664,821284360,41697505423,2202335611907, %T A223675 120016210924727,6715040320826544,384617913213951506, %U A223675 22513060559771644440,1345458233683987073442,82071805127975022481091 %N A223675 Number of n X n 0..1 arrays with rows and antidiagonals unimodal. %C A223675 Diagonal of A223680 %e A223675 Some solutions for n=3 %e A223675 ..1..1..1....1..1..0....0..1..1....0..0..1....0..1..0....0..1..0....0..1..1 %e A223675 ..0..1..1....1..1..0....1..1..0....1..1..1....1..1..1....0..0..0....1..0..0 %e A223675 ..0..0..1....0..1..1....1..1..1....0..1..0....0..0..0....0..1..1....0..0..0 %K A223675 nonn %O A223675 1,1 %A A223675 _R. H. Hardin_ Mar 25 2013