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 A239816 #6 Jun 02 2025 09:32:07 %S A239816 56,3951,232272,14544801,884977259,54668820459,3347474694032, %T A239816 205970817822022,12641836066488239,776862587801118702, %U A239816 47711236158517841564,2931070666588302434209,180038209753070897538954 %N A239816 Number of nX5 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, modulo 4. %C A239816 Column 5 of A239819 %H A239816 R. H. Hardin, <a href="/A239816/b239816.txt">Table of n, a(n) for n = 1..210</a> %e A239816 Some solutions for n=2 %e A239816 ..3..0..0..2..3....2..3..0..3..3....2..3..0..3..2....3..2..2..0..0 %e A239816 ..2..0..3..2..2....1..3..3..1..2....1..2..2..2..1....1..0..2..2..3 %K A239816 nonn %O A239816 1,1 %A A239816 _R. H. Hardin_, Mar 27 2014