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 A209501 #9 Jul 22 2025 21:46:17 %S A209501 202,133380,137627625,142937856372,148562491090605,154401817037192112, %T A209501 160472621147386212721,166781889837814691670272, %U A209501 173339279726971874626160091,180154479333345761550673106264 %N A209501 Number of nX6 0..4 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order. %C A209501 Column 6 of A209503 %H A209501 R. H. Hardin, <a href="/A209501/b209501.txt">Table of n, a(n) for n = 1..210</a> %e A209501 Some.solutions.for.n=4 %e A209501 ..0..1..0..2..0..1....0..1..0..2..3..0....0..1..0..1..2..3....0..1..0..1..0..0 %e A209501 ..0..2..0..1..1..3....0..2..0..4..4..4....0..2..0..4..4..4....0..2..0..3..1..2 %e A209501 ..0..1..0..2..4..3....0..1..0..1..3..1....0..1..0..1..2..3....0..1..0..1..4..1 %e A209501 ..0..2..0..1..2..3....0..2..0..2..1..4....0..2..0..4..2..4....0..2..0..4..0..4 %K A209501 nonn %O A209501 1,1 %A A209501 _R. H. Hardin_ Mar 09 2012