cp's OEIS Frontend

A209225 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 1 1 vertically.

%I A209225 #10 Jul 08 2018 21:31:22
%S A209225 9,81,126,196,504,1296,3312,8464,21712,55696,142544,364816,934992,
%T A209225 2396304,6136272,15713296,40258384,103144336,264177872,676624144,
%U A209225 1733335632,4440356496,11373699024,29133027856,74627823952,191168323984
%N A209225 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 1 1 vertically.
%C A209225 Row 4 of A209224.
%H A209225 R. H. Hardin, <a href="/A209225/b209225.txt">Table of n, a(n) for n = 1..210</a>
%F A209225 Empirical: a(n) = a(n-1) + 4*a(n-3) + 16*a(n-4) for n>7.
%F A209225 Empirical g.f.: x*(9 + 72*x + 45*x^2 + 34*x^3 - 160*x^4 - 1008*x^5 - 784*x^6) / ((1 + 4*x^2)*(1 - x - 4*x^2)). - _Colin Barker_, Jul 08 2018
%e A209225 Some solutions for n=4:
%e A209225   1 1 0 1     0 0 1 1     0 1 1 0     0 1 1 1     0 1 1 1
%e A209225   1 1 0 0     1 1 0 0     0 1 1 0     0 1 1 0     0 0 1 1
%e A209225   0 0 1 1     1 1 0 0     1 0 0 1     1 0 0 1     1 1 0 0
%e A209225   0 0 1 1     0 0 1 1     1 1 0 1     1 1 1 1     1 1 0 0
%Y A209225 Cf. A209224.
%K A209225 nonn
%O A209225 1,1
%A A209225 _R. H. Hardin_, Mar 06 2012