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 A240326 #6 Jun 02 2025 09:49:14 %S A240326 14,213,8091,189549,3898804,113751796,2343565571,58754628922, %T A240326 1550370290554,33299137997969,861337519232031,21016117833481545, %U A240326 474930037525217349,12220742975175544998,287468219917419510614 %N A240326 Number of nX6 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4. %C A240326 Column 6 of A240327 %H A240326 R. H. Hardin, <a href="/A240326/b240326.txt">Table of n, a(n) for n = 1..18</a> %e A240326 Some solutions for n=3 %e A240326 ..2..3..2..2..3..3....2..3..2..2..3..3....3..2..3..3..2..3....2..3..3..2..3..3 %e A240326 ..3..2..3..1..2..2....3..1..3..0..2..2....2..1..1..2..3..2....3..1..1..3..2..1 %e A240326 ..3..2..0..2..2..2....3..1..2..1..0..0....3..1..2..3..0..0....2..1..2..2..0..2 %K A240326 nonn %O A240326 1,1 %A A240326 _R. H. Hardin_, Apr 03 2014