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 A216030 #5 Jul 22 2025 23:29:27 %S A216030 2,136,7050,5219070,1355988481,4761748786964 %N A216030 Number of horizontal, vertical and diagonal neighbor colorings of the odd squares of an nX7 array with new integer colors introduced in row major order. %C A216030 Column 7 of A216031 %e A216030 Some solutions for n=4 %e A216030 ..x..0..x..1..x..2..x....x..0..x..1..x..2..x....x..0..x..1..x..2..x %e A216030 ..0..x..1..x..3..x..4....0..x..1..x..3..x..4....0..x..1..x..0..x..3 %e A216030 ..x..2..x..5..x..4..x....x..2..x..0..x..5..x....x..2..x..4..x..5..x %e A216030 ..2..x..3..x..0..x..3....2..x..3..x..6..x..0....6..x..5..x..7..x..1 %K A216030 nonn %O A216030 1,1 %A A216030 _R. H. Hardin_ Aug 30 2012