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A261549 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011. 1
80, 132, 269, 484, 871, 1702, 3230, 6084, 11656, 22140, 41998, 80163, 152575, 290154, 552862, 1052566, 2003661, 3815643, 7265371, 13832801, 26339615, 50153430, 95494793, 181830620, 346224829, 659237773, 1255247777, 2390111154, 4550973946 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A261553.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-2) +3*a(n-3) +a(n-4) -a(n-5) +a(n-6) -2*a(n-7) -2*a(n-8) -3*a(n-9) +2*a(n-10) -a(n-11) -7*a(n-12) +3*a(n-13) -4*a(n-14) -2*a(n-15) +2*a(n-16) for n>17

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Cf. A261553.

Sequence in context: A044003 A062376 A223087 * A068140 A224547 A204648

Adjacent sequences:  A261546 A261547 A261548 * A261550 A261551 A261552

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 24 2015

STATUS

approved

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Last modified September 16 06:18 EDT 2021. Contains 347469 sequences. (Running on oeis4.)