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A260364 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001111. 1
78, 127, 342, 700, 896, 2047, 4438, 6674, 12878, 27877, 46806, 84404, 175894, 316729, 562556, 1122802, 2100112, 3759241, 7255522, 13784466, 25036860, 47321615, 90142076, 165956528, 310385576, 589328265, 1095576864, 2041368188, 3857505346 (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-2) + 5*a(n-3) + 5*a(n-4) - 4*a(n-5) - 6*a(n-6) - 10*a(n-7) - 7*a(n-8) + 4*a(n-9) + 5*a(n-10) + 5*a(n-11) + 3*a(n-12).

Empirical g.f.: x*(78 + 127*x + 264*x^2 + 183*x^3 - 471*x^4 - 686*x^5 - 692*x^6 - 443*x^7 + 393*x^8 + 559*x^9 + 428*x^10 + 268*x^11) / ((1 - x)*(1 + x)^2*(1 + x^2)*(1 - x - 5*x^3 + x^4 + 3*x^5 + 2*x^6 + 3*x^7)). - Colin Barker, Dec 29 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 2 of A260370.

Sequence in context: A224666 A161596 A275218 * A185077 A042945 A044329

Adjacent sequences:  A260361 A260362 A260363 * A260365 A260366 A260367

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 23 2015

STATUS

approved

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Last modified April 20 12:58 EDT 2021. Contains 343135 sequences. (Running on oeis4.)