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 A241433 #5 Jun 02 2025 10:08:45 %S A241433 15,88,448,5915,45139,377314,4136727,34541924,418453966,4088141292, %T A241433 40962255699,430943324954,4031664281839 %N A241433 Number of nX6 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero 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 A241433 Column 6 of A241435 %e A241433 Some solutions for n=4 %e A241433 ..3..2..3..2..2..2....3..2..3..3..2..3....3..3..2..2..2..3....3..3..2..3..3..2 %e A241433 ..2..1..1..2..0..0....2..1..1..2..2..3....3..1..2..0..1..3....2..2..2..1..1..0 %e A241433 ..3..1..2..0..0..0....3..3..2..0..2..2....2..0..2..0..3..2....3..3..0..2..2..2 %e A241433 ..2..0..2..0..0..0....2..0..0..1..1..2....3..3..0..0..2..2....2..2..3..2..1..2 %K A241433 nonn %O A241433 1,1 %A A241433 _R. H. Hardin_, Apr 22 2014