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 A241355 #5 Jun 02 2025 10:06:28 %S A241355 20,103,641,5663,32942,247664,1904754,12340892,104529676,729080777, %T A241355 5436001228,44321599723 %N A241355 Number of nX7 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 zero plus the sum of the elements antidiagonally to its northeast, modulo 4. %C A241355 Column 7 of A241356 %e A241355 Some solutions for n=3 %e A241355 ..2..3..3..3..2..3..3....2..3..3..2..3..3..2....3..2..3..3..2..3..3 %e A241355 ..2..1..1..1..2..2..2....2..1..1..2..1..1..1....3..1..2..1..2..2..1 %e A241355 ..3..2..2..0..0..1..3....3..2..3..2..0..3..3....2..3..0..2..0..0..2 %K A241355 nonn %O A241355 1,1 %A A241355 _R. H. Hardin_, Apr 20 2014