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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. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified November 26 07:49 EST 2020. Contains 338632 sequences. (Running on oeis4.)