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 A241128 #6 Jul 23 2025 11:11:06 %S A241128 30,1965,132369,8974020,611547441,41661463219,2838552905280, %T A241128 193403197619803,13177423185201303,897837461485635262, %U A241128 61173728850055840649,4168043075184317942781,283987643903962340437622 %N A241128 Number of nX5 0..2 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..2 introduced in row major order. %C A241128 Column 5 of A241130 %H A241128 R. H. Hardin, <a href="/A241128/b241128.txt">Table of n, a(n) for n = 1..210</a> %e A241128 Some solutions for n=3 %e A241128 ..0..1..2..0..1....0..0..1..2..0....0..1..0..1..0....0..1..2..1..1 %e A241128 ..2..1..0..2..2....2..1..0..1..2....2..2..0..0..2....1..0..2..0..0 %e A241128 ..0..2..2..1..0....0..1..2..1..0....1..1..0..1..0....0..0..0..2..2 %K A241128 nonn %O A241128 1,1 %A A241128 _R. H. Hardin_, Apr 16 2014