A259888 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00000011.

67, 174, 653, 1853, 4662, 13704, 40955, 114098, 320200, 925820, 2650721, 7507059, 21402747, 61226147, 174506650, 497034443, 1418169080, 4046094873, 11534896627, 32891041296, 93814175452, 267543153907, 762917347904, 2175699989264

Offset

1,1

Links

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

Formula

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

Empirical g.f.: x*(67 - 27*x + 332*x^2 - 321*x^3 - 316*x^4 - 179*x^5 - 125*x^6 + 156*x^7) / (1 - 3*x + 3*x^2 - 11*x^3 + 8*x^4 + 5*x^5 + 5*x^6 + 2*x^7 - 3*x^8). - Colin Barker, Dec 27 2018

Example

Some solutions for n=4:
..1..0..0..1....0..0..0..1....1..1..0..0....0..0..0..0....1..0..0..1
..0..0..0..1....0..0..0..1....0..0..0..0....1..0..0..1....1..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..0....1..0..0..0....0..0..0..0....0..0..0..1
..1..0..0..1....0..1..0..0....1..0..0..1....1..0..0..1....0..0..0..1
..1..0..0..1....1..1..0..0....0..0..0..1....0..0..0..1....0..0..0..0

Crossrefs

Column 2 of A259894.

Sequence in context: A199824 A341278 A142544 * A142671 A144326 A119593

Adjacent sequences: A259885 A259886 A259887 * A259889 A259890 A259891

Keyword

nonn

Author

R. H. Hardin, Jul 07 2015

Status

approved