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 A241281 #5 Jun 02 2025 10:03:24 %S A241281 10,17,224,1800,20717,309657,5423164,113305157,2759021846,75062814060, %T A241281 2194626322280,66941258995665,2089883847033445,66049038598082087, %U A241281 2100649576601196394,67025504140569165794 %N A241281 Number of nX5 0..3 arrays with no element equal to one plus the sum of elements to its left or zero 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 A241281 Column 5 of A241283 %e A241281 Some solutions for n=3 %e A241281 ..3..2..3..2..2....3..3..2..3..2....3..2..3..3..3....3..3..2..3..2 %e A241281 ..2..1..2..1..0....2..1..1..0..3....0..3..2..1..2....2..1..3..1..3 %e A241281 ..2..2..3..2..0....2..2..0..2..2....2..0..0..2..2....3..2..3..2..2 %K A241281 nonn %O A241281 1,1 %A A241281 _R. H. Hardin_, Apr 18 2014