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 A240191 #6 Jun 02 2025 09:41:47 %S A240191 1,50,1908,40765,1399773,28061567,733907809,19388521135,394134037392, %T A240191 10503093361772,254148197056864,5694113978673887,149969038048214610, %U A240191 3469042519947752022,82120588801140926261,2085283919698276811475 %N A240191 Number of nX6 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it or three plus the sum of the elements diagonally to its northwest, modulo 4. %C A240191 Column 6 of A240192 %H A240191 R. H. Hardin, <a href="/A240191/b240191.txt">Table of n, a(n) for n = 1..17</a> %e A240191 Some solutions for n=4 %e A240191 ..2..0..0..0..0..0....2..0..0..0..0..0....2..0..0..0..0..0....2..0..0..0..0..0 %e A240191 ..1..2..0..0..2..0....1..2..2..0..2..0....1..2..2..0..2..2....1..0..2..0..0..2 %e A240191 ..1..2..0..2..2..0....1..2..2..2..0..2....2..1..2..3..2..0....2..3..2..2..2..0 %e A240191 ..2..3..0..0..2..0....2..3..0..2..0..0....1..2..2..3..3..2....1..3..2..1..1..2 %K A240191 nonn %O A240191 1,2 %A A240191 _R. H. Hardin_, Apr 02 2014