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 A207910 #7 Jul 22 2025 20:58:47 %S A207910 13,169,611,2209,13865,87025,417425,2002225,10896915,59305401, %T A207910 303611925,1554330625,8194919925,43206195321,224558681991, %U A207910 1167115069561,6108464797743,31970576988009,166753685864931,869761961442529 %N A207910 Number of 5Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 0 1 1 vertically. %C A207910 Row 5 of A207908 %H A207910 R. H. Hardin, <a href="/A207910/b207910.txt">Table of n, a(n) for n = 1..210</a> %e A207910 Some solutions for n=4 %e A207910 ..0..1..1..1....1..0..0..1....0..0..1..1....1..1..0..0....1..0..1..1 %e A207910 ..0..0..1..1....0..1..1..0....0..1..1..1....1..1..0..0....1..0..0..1 %e A207910 ..1..0..0..1....1..0..0..1....1..0..1..1....0..1..1..1....1..1..1..1 %e A207910 ..0..1..1..0....0..1..1..0....0..1..1..1....1..1..0..0....1..0..0..1 %e A207910 ..1..0..0..1....1..0..0..1....1..0..0..1....0..1..1..1....0..0..1..1 %K A207910 nonn %O A207910 1,1 %A A207910 _R. H. Hardin_ Feb 21 2012