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 A216089 #7 Jul 22 2025 23:30:25 %S A216089 5,409,21147,18378580,5116799368,20358402201792,14216413305846436, %T A216089 152834688133255075552,204451723997895101749260 %N A216089 Number of horizontal and antidiagonal neighbor colorings of the odd squares of a 7Xn array with new integer colors introduced in row major order. %C A216089 Row 7 of A216084 %e A216089 Some solutions for n=4 %e A216089 ..x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1 %e A216089 ..1..x..0..x....1..x..0..x....1..x..0..x....1..x..0..x....1..x..0..x %e A216089 ..x..1..x..2....x..1..x..2....x..1..x..2....x..1..x..2....x..2..x..0 %e A216089 ..3..x..4..x....2..x..1..x....3..x..4..x....3..x..0..x....0..x..3..x %e A216089 ..x..2..x..1....x..3..x..4....x..5..x..6....x..1..x..4....x..1..x..0 %e A216089 ..3..x..0..x....5..x..0..x....0..x..2..x....5..x..1..x....2..x..4..x %e A216089 ..x..2..x..5....x..1..x..0....x..0..x..6....x..4..x..3....x..3..x..1 %K A216089 nonn %O A216089 1,1 %A A216089 _R. H. Hardin_ Sep 01 2012