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A259765 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 or 00000101. 1
32, 49, 104, 201, 376, 745, 1494, 2897, 5610, 11065, 21780, 42461, 82984, 162977, 319406, 624529, 1222926, 2397205, 4694532, 9189573, 17999120, 35259025, 69046594, 135207885, 264815462, 518655749, 1015714340, 1989176813, 3895806716 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-2) + 2*a(n-3) + 6*a(n-4) + 2*a(n-5) - a(n-6) + 2*a(n-7) - a(n-8) for n>9.
Empirical g.f.: x*(32 + 49*x + 72*x^2 + 88*x^3 - 18*x^4 - 22*x^5 + 26*x^6 - 29*x^7 + 6*x^8) / (1 - x^2 - 2*x^3 - 6*x^4 - 2*x^5 + x^6 - 2*x^7 + x^8). - Colin Barker, Dec 26 2018
EXAMPLE
Some solutions for n=4:
..0..0..1....0..1..0....0..1..0....0..0..1....0..0..0....0..0..0....1..0..1
..0..1..0....0..0..1....0..0..1....0..1..0....0..0..0....0..0..0....0..1..0
..0..0..1....0..0..0....0..0..0....0..0..1....1..0..0....0..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..1..0....0..0..1....0..0..0....1..0..0....0..0..0....0..0..1
..0..0..1....0..0..1....0..1..0....0..1..0....0..1..0....1..0..1....0..1..0
CROSSREFS
Column 1 of A259770.
Sequence in context: A259770 A066472 A140172 * A256521 A037008 A316943
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 04 2015
STATUS
approved

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Last modified July 25 08:34 EDT 2024. Contains 374586 sequences. (Running on oeis4.)