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 A216343 #5 Jul 22 2025 23:31:29 %S A216343 15,409,115975,18378580,41521045376,20358402201792,148049849072167133, %T A216343 152834688133255075552,2562708952364833106990692 %N A216343 Number of horizontal and antidiagonal neighbor colorings of the even squares of a 7Xn array with new integer colors introduced in row major order. %C A216343 Row 7 of A216338 %e A216343 Some solutions for n=4 %e A216343 ..0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x %e A216343 ..x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1 %e A216343 ..1..x..2..x....2..x..0..x....1..x..0..x....2..x..0..x....1..x..2..x %e A216343 ..x..3..x..0....x..1..x..3....x..2..x..3....x..1..x..3....x..3..x..1 %e A216343 ..4..x..3..x....2..x..4..x....4..x..0..x....4..x..1..x....4..x..5..x %e A216343 ..x..4..x..1....x..0..x..5....x..4..x..5....x..3..x..2....x..3..x..0 %e A216343 ..2..x..0..x....3..x..1..x....0..x..4..x....5..x..6..x....6..x..3..x %K A216343 nonn %O A216343 1,1 %A A216343 _R. H. Hardin_ Sep 04 2012