A259945 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00000101.

34, 60, 156, 365, 801, 1825, 4272, 9840, 22444, 51509, 118673, 272721, 625828, 1437556, 3303988, 7590621, 17435081, 40053457, 92021928, 211404824, 485651892, 1115697125, 2563141785, 5888362641, 13527406476, 31076799084, 71393512556

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

Empirical g.f.: x*(34 + 26*x + 62*x^2 + 81*x^3 - 44*x^4 - 13*x^5 + 14*x^6 - 23*x^7 + 6*x^8) / ((1 + x)*(1 - 2*x + x^2 - 3*x^3 - 3*x^4 + 3*x^5 - 2*x^6 + x^7)). - Colin Barker, Dec 27 2018

Example

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

Crossrefs

Column 1 of A259952.

Sequence in context: A261314 A119454 A259952 * A303239 A280931 A115159

Adjacent sequences: A259942 A259943 A259944 * A259946 A259947 A259948

Keyword

nonn

Author

R. H. Hardin, Jul 10 2015

Status

approved