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%I #8 Dec 26 2018 11:52:12
%S 42,74,190,374,792,1514,3480,6542,14580,27866,62700,118718,266548,
%T 506810,1138004,2160350,4852180,9215834,20694708,39301214,88262564,
%U 167620346,376424388,714880094,1605429620,3048894554,6846969460,13003247390
%N Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 or 01010101.
%H R. H. Hardin, <a href="/A259737/b259737.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-2) + 9*a(n-4) + 4*a(n-6) - 6*a(n-8) + 4*a(n-10) for n>11.
%F Empirical g.f.: 2*x*(21 + 37*x + 53*x^2 + 113*x^3 + 17*x^4 + 50*x^5 + 9*x^6 - 74*x^7 - 8*x^8 + 52*x^9 + 12*x^10) / (1 - 2*x^2 - 9*x^4 - 4*x^6 + 6*x^8 - 4*x^10). - _Colin Barker_, Dec 26 2018
%e Some solutions for n=4:
%e ..0..0..1..0..0....1..0..1..0..1....1..0..1..0..1....0..1..0..1..0
%e ..0..1..0..0..0....0..1..0..1..0....0..0..0..1..0....1..0..1..0..0
%e ..1..0..1..0..1....1..0..1..0..1....1..0..1..0..0....0..1..0..1..0
%e ..0..1..0..1..0....0..1..0..1..0....0..1..0..1..0....1..0..1..0..1
%e ..1..0..1..0..0....0..0..1..0..1....0..0..1..0..1....0..1..0..1..0
%e ..0..1..0..1..0....0..1..0..0..0....0..1..0..1..0....1..0..1..0..1
%Y Column 3 of A259742.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jul 04 2015
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