A260277 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001011.

34, 46, 99, 202, 366, 714, 1428, 2750, 5291, 10334, 20111, 38936, 75595, 146976, 285323, 553794, 1075608, 2088887, 4055703, 7875257, 15293121, 29696093, 57662890, 111971304, 217428312, 422201962, 819834467, 1591965964, 3091293283

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 3*a(n-3) + a(n-4) + a(n-8) for n>10.

Empirical g.f.: x*(34 + 12*x + 53*x^2 + x^3 - 8*x^4 + 5*x^5 + 9*x^6 + 22*x^7 - x^8 - x^9) / (1 - x - 3*x^3 - x^4 - x^8). - Colin Barker, Dec 28 2018

Example

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

Crossrefs

Column 1 of A260284.

Sequence in context: A039327 A043150 A043930 * A045256 A302002 A370657

Adjacent sequences: A260274 A260275 A260276 * A260278 A260279 A260280

Keyword

nonn

Author

R. H. Hardin, Jul 22 2015

Status

approved