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 A216608 #7 Jul 22 2025 23:32:56 %S A216608 1,1,2,203,83437,6423127757,2043835395791757,324446722340564335642246 %N A216608 Number of horizontal, diagonal and antidiagonal neighbor colorings of the odd squares of an n X n array with new integer colors introduced in row major order. %C A216608 Diagonal of A216612 %e A216608 Some solutions for n=4 %e A216608 ..x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1 %e A216608 ..2..x..3..x....2..x..3..x....1..x..2..x....1..x..2..x....2..x..3..x %e A216608 ..x..4..x..1....x..4..x..1....x..3..x..4....x..0..x..3....x..4..x..1 %e A216608 ..5..x..0..x....1..x..5..x....2..x..5..x....3..x..2..x....1..x..3..x %K A216608 nonn %O A216608 1,3 %A A216608 _R. H. Hardin_ Sep 10 2012