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A261374 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101.

%I A261374 #11 Dec 30 2018 15:41:53
%S A261374 39,41,82,157,266,470,864,1553,2758,4960,8924,16001,28662,51503,92374,
%T A261374 165796,297284,533858,957252,1718645,3081790,5533474,9922064,17814980,
%U A261374 31944528,57356546,102846820,184661677,331120454,594527399,1066057422
%N A261374 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101.
%H A261374 R. H. Hardin, <a href="/A261374/b261374.txt">Table of n, a(n) for n = 1..210</a>
%F A261374 Empirical: a(n) = a(n-2) + 6*a(n-4) + 4*a(n-6) - a(n-8) for n > 9.
%F A261374 Empirical g.f.: x*(39 + 41*x + 43*x^2 + 116*x^3 - 50*x^4 + 67*x^5 - 50*x^6 - 23*x^7 + 9*x^8) / ((1 + x + 2*x^3 - x^4)*(1 - x - 2*x^3 - x^4)). - _Colin Barker_, Dec 30 2018
%e A261374 Some solutions for n=4:
%e A261374   0 1 0 1     0 0 1 0     1 0 0 1     0 1 0 0     1 0 0 0
%e A261374   1 0 1 0     0 0 0 1     1 0 0 0     1 0 0 0     0 1 0 1
%e A261374   0 1 0 1     1 0 1 0     0 1 0 1     0 1 0 1     1 0 1 0
%e A261374   1 0 1 0     0 1 0 1     1 0 1 0     1 0 1 0     0 0 0 1
%e A261374   0 1 0 1     0 0 1 0     0 1 0 1     0 1 0 0     0 0 1 0
%e A261374   1 0 1 0     0 1 0 1     1 0 0 0     0 0 1 0     1 1 0 1
%Y A261374 Column 2 of A261380.
%K A261374 nonn
%O A261374 1,1
%A A261374 _R. H. Hardin_, Aug 17 2015