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 A224167 #9 Mar 18 2025 20:54:37 %S A224167 4,100,4739,272130,16625026,1038484760,65713691148,4209750150062, %T A224167 273303096405547 %N A224167 Number of n X n 0..3 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing. %e A224167 Some solutions for n=3: %e A224167 ..0..1..0....0..0..0....0..3..2....2..0..0....0..0..1....0..0..2....0..0..1 %e A224167 ..2..1..1....0..2..0....0..3..2....2..0..0....0..2..2....0..1..3....1..2..3 %e A224167 ..3..3..2....2..2..0....1..3..2....2..3..0....1..2..3....0..3..3....2..3..3 %Y A224167 Diagonal of A224173. %K A224167 nonn,more %O A224167 1,1 %A A224167 _R. H. Hardin_, Mar 31 2013 %E A224167 Name corrected by _Andrew Howroyd_, Mar 18 2025