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 A239598 #5 Jun 02 2025 09:29:23 %S A239598 132,1030,9806,128347,1031560,12509870,120511910,1104844380, %T A239598 13122377637,109004201919,1143690420236,11250183216347,92332830515639 %N A239598 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 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 A239598 Column 6 of A239599 %e A239598 Some examples for n=3 %e A239598 ..3..0..0..0..2..2....3..2..2..0..2..0....3..0..0..2..2..0....3..0..0..2..2..2 %e A239598 ..2..3..0..2..2..2....2..1..2..2..0..2....2..3..2..0..2..2....2..3..2..0..2..2 %e A239598 ..3..2..2..0..2..0....3..2..2..0..2..0....3..2..0..0..0..0....3..2..0..0..0..2 %K A239598 nonn %O A239598 1,1 %A A239598 _R. H. Hardin_, Mar 22 2014