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 A208084 #8 Sep 04 2022 10:43:01 %S A208084 8,20,134,156,2664,1224,54504,9612,1119906,75492,23025384,592920, %T A208084 473447592,4656852,9735152022,36575388,200177107272,287266824, %U A208084 4116102713928,2256222924,84636562515282,17720604900,1740322886860296 %N A208084 Number of (n+1) X (n+1) 0..1 arrays with every 2 X 2 subblock having the same number of equal edges as its horizontal neighbors and a different number from its vertical neighbors, and new values 0..1 introduced in row major order. %C A208084 Diagonal of A208085. %H A208084 R. H. Hardin, <a href="/A208084/b208084.txt">Table of n, a(n) for n = 1..69</a> %e A208084 Some solutions for n=4 %e A208084 ..0..0..0..1..0....0..1..1..1..1....0..1..1..0..1....0..1..0..0..0 %e A208084 ..1..1..1..1..1....0..0..0..0..0....0..0..0..0..0....1..1..1..1..1 %e A208084 ..1..1..1..1..1....0..0..0..0..0....0..0..0..0..0....1..1..1..1..1 %e A208084 ..1..0..1..0..1....0..1..0..1..0....1..0..1..0..1....0..1..0..1..0 %e A208084 ..0..1..0..1..0....1..0..1..0..1....0..1..0..1..0....1..0..1..0..1 %Y A208084 Cf. A208085. %K A208084 nonn %O A208084 1,1 %A A208084 _R. H. Hardin_, Feb 23 2012