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 A207462 #7 Jun 18 2022 17:27:19 %S A207462 6,36,98,358,1152,3910,12994,43596,145678,487502,1630196,5453054, %T A207462 18238998,61008244,204063338,682563198,2283064944,7636504950, %U A207462 25542956650,85437392020,285775310062,955875582398,3197260259292,10694355621414 %N A207462 Number of n X 3 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically. %C A207462 Column 3 of A207467. %H A207462 R. H. Hardin, <a href="/A207462/b207462.txt">Table of n, a(n) for n = 1..210</a> %F A207462 Empirical: a(n) = 3*a(n-1) +a(n-2) -4*a(n-3) +11*a(n-4) +15*a(n-5) +4*a(n-6) -23*a(n-7) -17*a(n-8) +4*a(n-9) -7*a(n-10) +a(n-11) +a(n-12). %e A207462 Some solutions for n=4 %e A207462 ..1..0..0....0..0..1....1..1..0....1..1..1....1..0..0....0..0..1....1..1..0 %e A207462 ..0..0..1....0..0..1....1..0..1....1..1..0....1..0..1....0..0..1....0..0..1 %e A207462 ..0..0..1....0..0..1....1..0..1....1..0..0....1..0..1....1..1..1....0..0..1 %e A207462 ..0..1..0....1..1..1....0..1..0....1..0..1....1..0..1....1..1..0....1..0..0 %Y A207462 Cf. A207467. %K A207462 nonn %O A207462 1,1 %A A207462 _R. H. Hardin_, Feb 18 2012