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 A207554 #7 Jul 22 2025 20:34:44 %S A207554 622,386884,153718531,57282563287,21553876840265,8153351029428092, %T A207554 3082694275519480041,1165102509595020126200,440237796175859581158560, %U A207554 166342251234958398609975741,62849915005715508846282647469 %N A207554 Number of 6Xn 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 A207554 Row 6 of A207550 %H A207554 R. H. Hardin, <a href="/A207554/b207554.txt">Table of n, a(n) for n = 1..167</a> %e A207554 Some solutions for n=4 %e A207554 ..2..2..1..2....2..2..1..0....1..2..2..0....1..2..2..2....2..1..0..2 %e A207554 ..2..2..1..0....1..1..0..0....0..1..1..2....1..2..2..2....1..2..2..1 %e A207554 ..0..1..0..1....2..0..0..0....0..1..0..1....1..2..1..1....1..0..1..1 %e A207554 ..0..1..0..0....0..1..1..0....2..2..0..0....1..2..1..1....0..0..2..0 %e A207554 ..0..2..0..0....0..1..0..0....0..2..2..0....1..1..1..0....0..2..0..0 %e A207554 ..0..1..0..2....2..2..0..1....0..1..0..1....1..2..1..2....0..1..0..0 %K A207554 nonn %O A207554 1,1 %A A207554 _R. H. Hardin_ Feb 18 2012