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A260278 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001011. 1
46, 85, 230, 525, 1150, 2726, 6351, 14393, 33241, 77098, 177043, 407486, 941020, 2167955, 4992417, 11510489, 26530166, 61125209, 140873214, 324678646, 748199483, 1724247325, 3973747017, 9157675382, 21104202919, 48636225966 (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) + 7*a(n-3) + a(n-4) + a(n-5) - 7*a(n-6) - 4*a(n-7) + 3*a(n-9) for n>12.

Empirical g.f.: x*(46 + 39*x + 145*x^2 - 27*x^3 - 16*x^4 - 165*x^5 - 43*x^6 + 16*x^7 + 41*x^8 - 19*x^9 + 12*x^10 + 4*x^11) / ((1 + x^2 - x^3)*(1 - x - x^2 - 5*x^3 - x^4 + 3*x^5 + 3*x^6)). - Colin Barker, Dec 28 2018

EXAMPLE

Some solutions for n=4:

..0..0..0..0....0..0..0..0....0..0..1..0....1..1..0..1....1..0..1..0

..0..0..0..0....1..0..0..1....0..0..0..0....0..0..0..1....0..0..1..0

..0..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..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..0

..0..1..0..0....0..0..0..1....1..0..0..0....1..0..0..0....0..0..0..1

CROSSREFS

Column 2 of A260284.

Sequence in context: A113691 A188598 A057454 * A234260 A211330 A121929

Adjacent sequences:  A260275 A260276 A260277 * A260279 A260280 A260281

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 22 2015

STATUS

approved

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Last modified September 20 18:52 EDT 2019. Contains 327245 sequences. (Running on oeis4.)