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 A209737 #8 Jul 22 2025 21:56:23 %S A209737 1,6,2025,20611956,3309942226828,6126537051572916244, %T A209737 126664397726626418134051983 %N A209737 Number of n X n 0..5 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..5 introduced in row major order. %C A209737 Diagonal of A209744 %e A209737 Some solutions for n=5 %e A209737 ..0..0..0..0..1....0..0..0..1..1....0..0..0..0..0....0..0..0..0..0 %e A209737 ..1..2..1..2..0....1..2..1..2..0....1..2..1..2..1....1..2..1..2..1 %e A209737 ..0..1..0..0..3....1..0..0..0..3....0..0..0..0..0....0..1..0..2..3 %e A209737 ..1..2..1..2..2....3..3..4..1..0....1..2..1..2..1....1..4..4..0..2 %e A209737 ..0..2..3..1..0....1..4..5..4..0....0..0..1..0..0....5..5..2..0..1 %K A209737 nonn %O A209737 1,2 %A A209737 _R. H. Hardin_ Mar 12 2012