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 A207089 #8 Mar 04 2018 17:45:00 %S A207089 7,49,241,1393,7915,44065,248525,1398065,7855615,44186849,248469913, %T A207089 1397116033,7856468163,44178243889,248421665301,1396925252001, %U A207089 7855169243255,44171085215953,248382373987585,1396700728871121 %N A207089 Number of 3 X n 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically. %C A207089 Row 3 of A207088. %H A207089 R. H. Hardin, <a href="/A207089/b207089.txt">Table of n, a(n) for n = 1..210</a> %F A207089 Empirical: a(n) = 2*a(n-1) + 11*a(n-2) + 48*a(n-3) + 29*a(n-4) + 6*a(n-5) - 111*a(n-6) - 8*a(n-7) - 32*a(n-8) + 64*a(n-9). %F A207089 Empirical g.f.: x*(7 + 35*x + 66*x^2 + 36*x^3 - 77*x^4 - 119*x^5 - 40*x^6 + 32*x^7 + 64*x^8) / (1 - 2*x - 11*x^2 - 48*x^3 - 29*x^4 - 6*x^5 + 111*x^6 + 8*x^7 + 32*x^8 - 64*x^9). - _Colin Barker_, Mar 04 2018 %e A207089 Some solutions for n=4: %e A207089 ..0..1..0..1....0..1..1..1....1..1..0..0....0..0..1..0....1..0..1..1 %e A207089 ..1..0..0..1....1..0..0..1....1..1..1..1....0..1..0..1....1..0..1..0 %e A207089 ..0..1..0..0....0..0..1..0....1..1..0..0....0..1..0..0....0..0..1..0 %Y A207089 Cf. A207088. %K A207089 nonn %O A207089 1,1 %A A207089 _R. H. Hardin_, Feb 15 2012