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A260170 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00010001. 1
40, 74, 183, 409, 950, 2221, 5235, 12063, 28230, 65845, 153721, 357676, 835423, 1947580, 4542768, 10590805, 24709416, 57615880, 134380567, 313384529, 730933689, 1704584262, 3975550976, 9271665730, 21623741651, 50430265244 (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) + 2*a(n-2) + 2*a(n-3) + 6*a(n-4) - 8*a(n-5) - 3*a(n-6) - 4*a(n-7) - 10*a(n-8) - 4*a(n-9) + 8*a(n-10) for n>11.

Empirical g.f.: x*(40 + 34*x + 29*x^2 - 2*x^3 - 213*x^4 - 37*x^5 - 90*x^6 - 122*x^7 + 72*x^8 + 152*x^9 - 60*x^10) / (1 - x - 2*x^2 - 2*x^3 - 6*x^4 + 8*x^5 + 3*x^6 + 4*x^7 + 10*x^8 + 4*x^9 - 8*x^10). - Colin Barker, Dec 28 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 1 of A260177.

Sequence in context: A064635 A098517 A260177 * A260544 A260537 A044106

Adjacent sequences:  A260167 A260168 A260169 * A260171 A260172 A260173

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 17 2015

STATUS

approved

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Last modified July 20 05:19 EDT 2019. Contains 325168 sequences. (Running on oeis4.)