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 A207547 #9 Jul 22 2025 20:34:08 %S A207547 216,46656,7169168,1058580304,151596413811,21553876840265, %T A207547 3054158366460488,432330439527473859,61173307041263346298, %U A207547 8654652528939212249147,1224376462168696645919384 %N A207547 Number of nX5 0..2 arrays avoiding the pattern z-2 z-1 z in any row, column, nw-to-se diagonal or ne-to-sw antidiagonal. %C A207547 Column 5 of A207550 %H A207547 R. H. Hardin, <a href="/A207547/b207547.txt">Table of n, a(n) for n = 1..210</a> %e A207547 Some solutions for n=4 %e A207547 ..0..1..0..1..0....2..1..1..0..0....0..0..1..1..1....0..2..0..2..2 %e A207547 ..1..2..1..1..2....1..2..0..0..2....0..2..1..0..2....0..0..2..2..1 %e A207547 ..0..2..1..2..0....0..2..1..2..0....2..2..0..1..0....2..1..2..0..2 %e A207547 ..0..0..2..1..0....2..1..1..0..0....0..2..2..0..2....1..0..0..1..1 %K A207547 nonn %O A207547 1,1 %A A207547 _R. H. Hardin_ Feb 18 2012