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A260287
Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001001.
1
48, 104, 274, 560, 966, 2300, 4762, 8252, 17470, 38160, 71698, 142360, 304646, 599716, 1172578, 2447716, 4949782, 9718248, 19837162, 40474736, 80338222, 161965772, 330213194, 661573644, 1327566094, 2695382016, 5430701122
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 4*a(n-3) + 5*a(n-4) + 2*a(n-5) + 8*a(n-6) + 8*a(n-7) - 4*a(n-8) - 8*a(n-9) for n>10.
Empirical g.f.: 2*x*(24 + 52*x + 137*x^2 + 184*x^3 + 155*x^4 + 294*x^5 + 280*x^6 - 88*x^7 - 256*x^8 - 96*x^9) / (1 - 4*x^3 - 5*x^4 - 2*x^5 - 8*x^6 - 8*x^7 + 4*x^8 + 8*x^9). - Colin Barker, Dec 29 2018
EXAMPLE
Some solutions for n=4:
..0..0..0....0..0..0....0..0..1....0..0..0....1..0..0....0..0..0....0..0..1
..1..0..0....0..0..1....1..1..0....0..0..0....0..0..0....0..1..1....0..1..0
..0..0..1....0..0..0....0..0..0....1..0..0....0..1..0....0..0..0....0..0..0
..0..0..0....0..0..0....0..0..0....0..0..1....0..1..0....0..0..0....0..0..0
..0..0..0....1..0..0....0..1..0....0..0..0....0..0..0....1..1..0....1..1..0
..1..0..0....1..0..0....0..0..1....0..1..0....1..0..0....0..0..1....1..0..0
CROSSREFS
Column 1 of A260294.
Sequence in context: A259994 A113797 A260294 * A187931 A191837 A044235
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 22 2015
STATUS
approved