A259766 - OEIS

A259766

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

49, 87, 167, 299, 564, 1086, 2045, 3870, 7371, 14001, 26647, 50766, 96574, 183815, 350088, 666497, 1268925, 2416285, 4600654, 8759750, 16679685, 31759384, 60472021, 115144725, 219245665, 417461876, 794885812, 1513533557, 2881900030

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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) + a(n-3) + 2*a(n-4) - 2*a(n-5) + 2*a(n-6) - 4*a(n-7) - 3*a(n-8) + 2*a(n-9) - 4*a(n-10) + 2*a(n-11) for n>12.

Empirical g.f.: x*(49 + 38*x + 31*x^2 - 4*x^3 - 87*x^4 - 20*x^5 - 162*x^6 - 67*x^7 + x^8 - 96*x^9 + 78*x^10 - 6*x^11) / (1 - x - x^2 - x^3 - 2*x^4 + 2*x^5 - 2*x^6 + 4*x^7 + 3*x^8 - 2*x^9 + 4*x^10 - 2*x^11). - Colin Barker, Dec 27 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 2 of A259770.

Sequence in context: A250074 A247678 A093894 * A273937 A326257 A231275

Adjacent sequences: A259763 A259764 A259765 * A259767 A259768 A259769

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 04 2015

STATUS

approved