A259636 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 or 00000001.

29, 64, 171, 365, 813, 1964, 4499, 10188, 23712, 54825, 125645, 289829, 669250, 1540429, 3548858, 8183956, 18857787, 43449225, 100146613, 230800868, 531852951, 1225710880, 2824793748, 6509782737, 15002141393, 34573642293, 79676799626

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) + a(n-4) - 3*a(n-5) - 3*a(n-6) for n>7.

Empirical g.f.: x*(29 + 35*x + 78*x^2 - 15*x^3 - 72*x^4 - 46*x^5 + 5*x^6) / (1 - x - x^2 - 5*x^3 - x^4 + 3*x^5 + 3*x^6). - Colin Barker, Dec 26 2018

Example

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

Crossrefs

Column 2 of A259642.

Sequence in context: A338529 A039516 A134547 * A240169 A044131 A044512

Adjacent sequences: A259633 A259634 A259635 * A259637 A259638 A259639

Keyword

nonn

Author

R. H. Hardin, Jul 02 2015

Status

approved