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 A239403 #6 Jun 02 2025 09:27:34 %S A239403 64,9811,1504399,222457036,33522573911,5072216819342,765206237815409, %T A239403 115478426410506313,17442858177037612521,2634917770699112523591, %U A239403 398013557514665813580770,60124899058707592070564461 %N A239403 Number of nX6 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of elements above it, modulo 4. %C A239403 Column 6 of A239405 %H A239403 R. H. Hardin, <a href="/A239403/b239403.txt">Table of n, a(n) for n = 1..210</a> %e A239403 Some solutions for n=2 %e A239403 ..3..1..3..3..0..1....0..0..0..3..1..3....3..1..3..3..1..3....0..3..3..0..1..3 %e A239403 ..2..1..2..0..1..0....0..0..0..2..2..3....2..1..3..0..0..0....0..3..3..0..2..3 %K A239403 nonn %O A239403 1,1 %A A239403 _R. H. Hardin_, Mar 17 2014