A259994 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00000101.

48, 99, 284, 641, 1228, 2943, 7284, 15683, 34012, 81017, 186614, 409327, 928000, 2153685, 4861084, 10890015, 24884066, 56836211, 128191444, 290174291, 661545278, 1501862093, 3397770104, 7714956093, 17539682412, 39769793417

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 5*a(n-3) + 7*a(n-4) - 7*a(n-5) - 5*a(n-7).

Empirical g.f.: x*(48 + 51*x + 185*x^2 + 117*x^3 - 244*x^4 - 62*x^5 - 159*x^6) / ((1 - x)*(1 - 5*x^3 - 12*x^4 - 5*x^5 - 5*x^6)). - Colin Barker, Dec 27 2018

Example

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

Crossrefs

Column 1 of A260001.

Sequence in context: A260248 A260001 A260241 * A113797 A260294 A260287

Adjacent sequences: A259991 A259992 A259993 * A259995 A259996 A259997

Keyword

nonn

Author

R. H. Hardin, Jul 12 2015

Status

approved