A260201 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00010001.

44, 80, 207, 479, 1163, 2864, 6895, 16690, 40598, 98367, 238383, 578373, 1402450, 3400311, 8246174, 19996576, 48488613, 117582381, 285129777, 691413726, 1676626449, 4065695950, 9858990214, 23907290449, 57973356043, 140580903753

Offset

1,1

Links

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

Formula

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

Empirical g.f.: x*(44 + 36*x + 83*x^2 - 28*x^3 - 11*x^4 - 17*x^5 - 21*x^6 - 5*x^7 + 12*x^8) / (1 - x - x^2 - 5*x^3 - 2*x^4 - x^5 + x^7 + x^8). - Colin Barker, Dec 28 2018

Example

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

Crossrefs

Column 2 of A260207.

Sequence in context: A043209 A043989 A050272 * A112721 A195816 A118087

Adjacent sequences: A260198 A260199 A260200 * A260202 A260203 A260204

Keyword

nonn

Author

R. H. Hardin, Jul 19 2015

Status

approved