A259765 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 or 00000101.

32, 49, 104, 201, 376, 745, 1494, 2897, 5610, 11065, 21780, 42461, 82984, 162977, 319406, 624529, 1222926, 2397205, 4694532, 9189573, 17999120, 35259025, 69046594, 135207885, 264815462, 518655749, 1015714340, 1989176813, 3895806716

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-2) + 2*a(n-3) + 6*a(n-4) + 2*a(n-5) - a(n-6) + 2*a(n-7) - a(n-8) for n>9.

Empirical g.f.: x*(32 + 49*x + 72*x^2 + 88*x^3 - 18*x^4 - 22*x^5 + 26*x^6 - 29*x^7 + 6*x^8) / (1 - x^2 - 2*x^3 - 6*x^4 - 2*x^5 + x^6 - 2*x^7 + x^8). - Colin Barker, Dec 26 2018

Example

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

Crossrefs

Column 1 of A259770.

Sequence in context: A259770 A066472 A140172 * A256521 A037008 A316943

Adjacent sequences: A259762 A259763 A259764 * A259766 A259767 A259768

Keyword

nonn

Author

R. H. Hardin, Jul 04 2015

Status

approved