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 A224152 #10 Dec 30 2023 21:41:47 %S A224152 2,12,89,574,3469,20065,114537,650819,3705824,21181267,121617211, %T A224152 701255335,4058735341,23565789117,137190976378,800437914689, %U A224152 4678794395883,27391873966579,160581355210547,942493889605853 %N A224152 Number of n X n 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing. %C A224152 Diagonal of A224158. %H A224152 R. H. Hardin, <a href="/A224152/b224152.txt">Table of n, a(n) for n = 1..23</a> %e A224152 Some solutions for n=3 %e A224152 ..0..0..0....1..1..0....1..0..0....0..0..0....1..1..0....0..1..0....0..0..0 %e A224152 ..0..0..0....1..1..0....0..1..0....0..0..0....1..0..0....1..1..1....0..1..0 %e A224152 ..1..0..0....1..0..0....1..0..0....0..0..1....0..1..0....1..1..1....1..0..0 %Y A224152 Cf. A224158. %K A224152 nonn %O A224152 1,1 %A A224152 _R. H. Hardin_, Mar 31 2013