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 A259422 #6 Jun 02 2025 11:51:04 %S A259422 142,1366,12953,123306,1172659,11155819,106118138,1009466878, %T A259422 9602626846,91346008647,868937609248,8265855103277,78629755083895, %U A259422 747973270226802,7115169104694298,67683744437222992,643848260656503313 %N A259422 Number of (n+1)X(3+1) 0..1 arrays with each 2X2 subblock having clockwise pattern 0000 0001 0011 or 0111. %C A259422 Column 3 of A259427 %H A259422 R. H. Hardin, <a href="/A259422/b259422.txt">Table of n, a(n) for n = 1..210</a> %F A259422 Empirical: a(n) = 6*a(n-1) +41*a(n-2) -44*a(n-3) -278*a(n-4) +51*a(n-5) +426*a(n-6) +36*a(n-7) -131*a(n-8) %e A259422 Some solutions for n=4 %e A259422 ..0..1..0..0....1..0..0..0....0..0..1..0....1..0..1..1....1..1..0..0 %e A259422 ..1..1..0..0....1..0..1..1....1..0..0..0....0..0..0..1....0..1..0..1 %e A259422 ..0..0..0..1....1..0..0..0....0..0..1..0....0..0..0..0....0..1..0..0 %e A259422 ..1..0..1..1....1..1..1..1....1..0..0..0....0..0..0..0....0..0..0..0 %e A259422 ..0..0..0..0....0..0..1..0....1..0..0..0....0..1..1..1....0..0..0..0 %Y A259422 Cf. A259427 %K A259422 nonn %O A259422 1,1 %A A259422 _R. H. Hardin_, Jun 26 2015