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 A201796 #8 Jul 22 2025 16:20:27 %S A201796 1,85,4057,988589,722587629 %N A201796 Number of zero-sum n X n -2..2 arrays with every element unequal to at most two horizontal and vertical neighbors. %C A201796 Diagonal of A201803 %e A201796 Some solutions for n=3 %e A201796 ..2..0..0....0..0..0....0..0.-2...-2..0.-1....2.-1.-1...-1..1..2....0.-2.-2 %e A201796 .-2.-2.-2....1..0..0....0..0..0....0..0.-1....1.-1.-1....1..1.-2....1..1..1 %e A201796 ..2..1..1....1..0.-2....2..2.-2....2..2..0....1..0..0....2.-2.-2....0..1..0 %K A201796 nonn %O A201796 1,2 %A A201796 _R. H. Hardin_ Dec 05 2011