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A261704 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00000111. 1

%I #8 Dec 31 2018 05:34:46

%S 48,76,172,338,628,1298,2752,5526,10972,22462,46160,93354,188556,

%T 384154,782784,1587790,3221196,6550678,13318688,27044962,54927964,

%U 111631314,226840208,460792838,936118684,1902095342,3864635632,7851378074

%N Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00000111.

%H R. H. Hardin, <a href="/A261704/b261704.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + a(n-2) + a(n-3) + 5*a(n-4) - 3*a(n-5) - 5*a(n-6) + 3*a(n-7) - 4*a(n-8) + 2*a(n-9) for n>11.

%F Empirical g.f.: 2*x*(24 + 14*x + 24*x^2 + 21*x^3 - 99*x^4 - 38*x^5 + 48*x^6 - 45*x^7 + 47*x^8 - 6*x^9 - 2*x^10) / ((1 - x)*(1 - x^2 - 2*x^3 - 7*x^4 - 4*x^5 + x^6 - 2*x^7 + 2*x^8)). - _Colin Barker_, Dec 31 2018

%e Some solutions for n=7:

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

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

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

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

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

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

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

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

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

%Y Column 1 of A261709.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 28 2015

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Last modified February 23 03:01 EST 2024. Contains 370265 sequences. (Running on oeis4.)