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.

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

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A260284 A260285 A260286 * A260288 A260289 A260290

Keyword

nonn

Author

R. H. Hardin, Jul 22 2015

Status

approved