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 A223795 #8 Jul 23 2025 04:31:46 %S A223795 4,256,110116,151310069,453578376041,2401987689157097, %T A223795 19618352087687868206,225161556703631799074083, %U A223795 3396567436573176749810085543,64088930629934993395801694394536 %N A223795 Number of n X n 0..3 arrays with rows and antidiagonals unimodal. %C A223795 Diagonal of A223801 %H A223795 R. H. Hardin, <a href="/A223795/b223795.txt">Table of n, a(n) for n = 1..11</a> %e A223795 Some solutions for n=3 %e A223795 ..0..0..0....0..1..1....2..1..1....2..3..1....2..1..0....2..1..1....2..3..2 %e A223795 ..3..0..0....0..2..0....0..3..2....0..3..0....0..2..3....0..3..3....1..3..1 %e A223795 ..0..0..0....1..2..2....1..2..3....0..0..1....3..3..1....0..2..2....3..3..1 %K A223795 nonn %O A223795 1,1 %A A223795 _R. H. Hardin_ Mar 27 2013