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A259636 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 or 00000001. 1
29, 64, 171, 365, 813, 1964, 4499, 10188, 23712, 54825, 125645, 289829, 669250, 1540429, 3548858, 8183956, 18857787, 43449225, 100146613, 230800868, 531852951, 1225710880, 2824793748, 6509782737, 15002141393, 34573642293, 79676799626 (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) + 5*a(n-3) + a(n-4) - 3*a(n-5) - 3*a(n-6) for n>7.

Empirical g.f.: x*(29 + 35*x + 78*x^2 - 15*x^3 - 72*x^4 - 46*x^5 + 5*x^6) / (1 - x - x^2 - 5*x^3 - x^4 + 3*x^5 + 3*x^6). - Colin Barker, Dec 26 2018

EXAMPLE

Some solutions for n=4:

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

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

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

CROSSREFS

Column 2 of A259642.

Sequence in context: A092222 A039516 A134547 * A240169 A044131 A044512

Adjacent sequences:  A259633 A259634 A259635 * A259637 A259638 A259639

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 02 2015

STATUS

approved

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Last modified September 27 22:36 EDT 2020. Contains 337388 sequences. (Running on oeis4.)