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 A223874 #6 Jul 23 2025 04:37:16 %S A223874 610,372100,90648289,13394424591,1705349067795,222723966999899, %T A223874 31033209360480497,4506383006996850479,664129167006783939721, %U A223874 98073753144458822374289,14467688866723338479395847 %N A223874 Number of nX6 0..3 arrays with rows, diagonals and antidiagonals unimodal. %C A223874 Column 6 of A223876 %H A223874 R. H. Hardin, <a href="/A223874/b223874.txt">Table of n, a(n) for n = 1..81</a> %e A223874 Some solutions for n=3 %e A223874 ..0..0..0..1..1..0....0..0..0..3..2..1....0..0..0..0..2..2....0..0..0..0..3..3 %e A223874 ..0..0..0..1..2..3....0..0..0..1..3..3....0..0..0..0..2..3....0..0..0..1..3..2 %e A223874 ..0..0..0..2..2..2....0..0..0..0..3..1....0..0..0..1..1..0....0..0..0..2..1..0 %K A223874 nonn %O A223874 1,1 %A A223874 _R. H. Hardin_ Mar 28 2013