A260063 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00000111.

48, 91, 256, 557, 956, 2131, 5088, 10235, 20242, 45355, 99168, 201609, 422888, 924655, 1959672, 4072719, 8679398, 18623703, 39243888, 82677405, 176286268, 374837907, 791289656, 1676354907, 3565263074, 7557825083, 15992930920

Offset

1,1

Links

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

Formula

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

Empirical g.f.: x*(48 + 43*x + 165*x^2 + 109*x^3 - 205*x^4 - 64*x^5) / (1 - x - 4*x^3 - 5*x^4 + 5*x^5 + 2*x^6). - Colin Barker, Dec 28 2018

Example

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

Crossrefs

Column 1 of A260070.

Sequence in context: A260980 A260070 A260973 * A211723 A274899 A218486

Adjacent sequences: A260060 A260061 A260062 * A260064 A260065 A260066

Keyword

nonn

Author

R. H. Hardin, Jul 14 2015

Status

approved