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 A239862 #6 Jun 02 2025 09:35:28 %S A239862 8,5,130,484,4549,19065,77212,970717,4024283,29283865,237306256, %T A239862 903816798,6001392838,42830861947,200921301635,1351900199288, %U A239862 8836338066911,44530526981817,287975221682482,1867118985367733 %N A239862 Number of 5Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4. %C A239862 Row 5 of A239858 %H A239862 R. H. Hardin, <a href="/A239862/b239862.txt">Table of n, a(n) for n = 1..22</a> %e A239862 Some solutions for n=4 %e A239862 ..3..2..3..2....3..2..3..3....2..3..3..2....3..2..3..3....3..2..3..3 %e A239862 ..2..1..1..3....2..1..2..2....3..1..1..3....2..1..1..2....2..1..2..2 %e A239862 ..3..1..3..2....3..0..0..0....3..2..2..0....3..2..2..2....3..0..0..2 %e A239862 ..3..2..2..2....3..1..2..0....3..1..3..0....2..3..0..0....3..2..2..0 %e A239862 ..2..3..0..0....2..1..2..2....2..1..0..2....3..2..0..0....2..3..0..2 %K A239862 nonn %O A239862 1,1 %A A239862 _R. H. Hardin_, Mar 28 2014