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 A222577 #5 Jul 23 2025 02:47:27 %S A222577 41,59,500,4790,30766,543064,4102865,98594434,860815001,23440266996, %T A222577 218791888336,6191473414860,58972215470543,1688437861153179, %U A222577 16197610528535176 %N A222577 Number of 5Xn 0..2 arrays with no more than floor(5Xn/2) elements unequal to at least one horizontal, diagonal or antidiagonal neighbor, with new values introduced in row major 0..2 order. %C A222577 Row 5 of A222573 %e A222577 Some solutions for n=3 %e A222577 ..0..0..0....0..0..0....0..0..0....0..0..0....0..1..2....0..0..0....0..0..0 %e A222577 ..1..0..0....0..0..0....0..0..0....0..0..0....2..1..2....0..0..0....1..0..0 %e A222577 ..2..0..2....0..0..0....1..0..0....0..0..0....1..1..1....0..0..0....1..0..1 %e A222577 ..0..0..0....1..0..1....0..0..2....1..0..2....1..1..1....0..0..1....0..0..0 %e A222577 ..0..0..0....2..1..0....1..0..0....2..0..1....1..1..1....0..0..0....0..0..0 %K A222577 nonn %O A222577 1,1 %A A222577 _R. H. Hardin_ Feb 25 2013