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 A216465 #5 Jul 22 2025 23:32:43 %S A216465 15,203,36401,4213597,8195008751,3376465219485,22530453266592757, %T A216465 20538493137072741201 %N A216465 Number of horizontal, diagonal and antidiagonal neighbor colorings of the even squares of a 7Xn array with new integer colors introduced in row major order. %C A216465 Row 7 of A216460 %e A216465 Some solutions for n=4 %e A216465 ..0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x %e A216465 ..x..2..x..0....x..2..x..0....x..2..x..0....x..2..x..0....x..2..x..0 %e A216465 ..0..x..3..x....0..x..3..x....0..x..1..x....0..x..3..x....0..x..3..x %e A216465 ..x..4..x..2....x..1..x..2....x..2..x..3....x..4..x..1....x..2..x..4 %e A216465 ..5..x..0..x....4..x..5..x....1..x..4..x....1..x..5..x....1..x..5..x %e A216465 ..x..3..x..2....x..6..x..3....x..0..x..1....x..6..x..4....x..4..x..1 %e A216465 ..2..x..1..x....5..x..4..x....4..x..3..x....3..x..0..x....2..x..3..x %K A216465 nonn %O A216465 1,1 %A A216465 _R. H. Hardin_ Sep 07 2012