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 A223880 #5 Jul 23 2025 04:37:57 %S A223880 4096,16777216,6066668157,411716468431,12351748855245,222723966999899, %T A223880 2864914204785815,29313435510121943,256460553486002269, %U A223880 2005690447094149401 %N A223880 Number of 6Xn 0..3 arrays with rows, diagonals and antidiagonals unimodal. %C A223880 Row 6 of A223876 %e A223880 Some solutions for n=3 %e A223880 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A223880 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A223880 ..0..0..2....0..0..1....0..0..1....0..0..2....0..0..0....0..0..2....0..0..0 %e A223880 ..2..2..3....1..2..1....1..2..2....1..2..1....3..0..0....2..2..0....0..0..3 %e A223880 ..2..3..1....0..3..3....1..3..2....2..1..1....2..0..0....0..2..2....0..1..2 %e A223880 ..0..3..3....0..1..3....0..2..2....0..0..0....2..3..0....0..3..1....1..2..2 %K A223880 nonn %O A223880 1,1 %A A223880 _R. H. Hardin_ Mar 28 2013