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 A261548 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011. 1

%I

%S 48,80,170,336,652,1293,2588,5100,9996,19788,39102,76977,151492,

%T 298988,589456,1160987,2287512,4509948,8887914,17512005,34511260,

%U 68019255,134042352,264143499,520558296,1025893511,2021700618,3984123909

%N Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011.

%H R. H. Hardin, <a href="/A261548/b261548.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-2) + 2*a(n-3) + 6*a(n-4) - 8*a(n-6) - 2*a(n-7) - 5*a(n-8) - 2*a(n-9) + 5*a(n-10) + 2*a(n-12) for n>14.

%F Empirical g.f.: x*(48 + 80*x + 74*x^2 + 80*x^3 - 136*x^4 - 199*x^5 - 24*x^6 - 70*x^7 + 82*x^8 + 178*x^9 + 40*x^10 + 77*x^11 + 12*x^12 + 7*x^13) / (1 - 2*x^2 - 2*x^3 - 6*x^4 + 8*x^6 + 2*x^7 + 5*x^8 + 2*x^9 - 5*x^10 - 2*x^12). - _Colin Barker_, Dec 30 2018

%e Some solutions for n=4:

%e ..0..0..1....0..0..0....1..0..1....0..0..0....1..0..0....1..0..0....0..0..1

%e ..0..1..0....0..1..0....0..0..1....0..1..0....0..0..0....0..1..0....0..0..0

%e ..0..0..1....1..0..0....0..0..0....1..0..0....1..0..0....0..0..0....0..0..1

%e ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0

%e ..0..1..1....0..0..0....1..0..0....0..0..0....1..0..0....0..1..0....0..0..1

%e ..0..0..0....0..1..0....0..1..0....0..0..1....0..0..0....1..0..1....1..1..0

%Y Column 1 of A261553.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 24 2015

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Last modified January 23 01:30 EST 2020. Contains 331166 sequences. (Running on oeis4.)