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A260099 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00010101. 1
48, 85, 206, 472, 1116, 2575, 6068, 14096, 33044, 76925, 180064, 419884, 981640, 2290567, 5352572, 12495004, 29189140, 68152069, 159185904, 371714924, 868161704, 2027353439, 4734819476, 11057193964, 25823175228, 60305591933 (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) = 2*a(n-2) + 2*a(n-3) + 11*a(n-4) + 6*a(n-5) + 2*a(n-6) + 6*a(n-7) - 8*a(n-8) + 2*a(n-9) for n>10.

Empirical g.f.: x*(48 + 85*x + 110*x^2 + 206*x^3 + 6*x^4 - 4*x^5 + 20*x^6 - 172*x^7 + 112*x^8 - 20*x^9) / (1 - 2*x^2 - 2*x^3 - 11*x^4 - 6*x^5 - 2*x^6 - 6*x^7 + 8*x^8 - 2*x^9). - Colin Barker, Dec 28 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 1 of A260106.

Sequence in context: A062902 A058229 A260106 * A224546 A247720 A204647

Adjacent sequences:  A260096 A260097 A260098 * A260100 A260101 A260102

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 16 2015

STATUS

approved

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Last modified November 29 18:41 EST 2021. Contains 349416 sequences. (Running on oeis4.)