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 A223658 #7 Jul 23 2025 04:21:25 %S A223658 4,256,141046,761845474,44626165058452 %N A223658 Number of n X n 0..3 arrays with row sums unimodal and column sums inverted unimodal. %C A223658 Diagonal of A223663 %e A223658 Some solutions for n=3 %e A223658 ..1..0..2....0..0..1....0..0..1....0..1..0....3..0..2....2..1..3....2..0..2 %e A223658 ..3..2..3....2..0..1....2..0..3....3..3..2....1..2..2....3..2..1....0..2..2 %e A223658 ..0..1..2....2..1..2....0..2..2....3..1..1....2..2..0....0..2..2....3..1..3 %K A223658 nonn %O A223658 1,1 %A A223658 _R. H. Hardin_ Mar 25 2013