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A260920 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 00101011 or 01010101. 1
36, 48, 104, 186, 297, 491, 883, 1489, 2534, 4289, 7421, 12581, 21537, 36634, 62796, 106888, 182812, 311578, 532706, 908294, 1551949, 2647450, 4522307, 7716224, 13177700, 22488756, 38401007, 65541083, 111905468, 191009570, 326112380 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-2) + 3*a(n-4) + 2*a(n-5) + 2*a(n-6) + 3*a(n-7) + a(n-8) for n>10.
Empirical g.f.: x*(36 + 48*x + 68*x^2 + 138*x^3 + 85*x^4 + 89*x^5 + 106*x^6 + 28*x^7 + x^9) / (1 - x^2 - 3*x^4 - 2*x^5 - 2*x^6 - 3*x^7 - x^8). - Colin Barker, Dec 29 2018
EXAMPLE
Some solutions for n=4:
..1..0..0....0..1..0....0..0..1....0..1..1....0..1..1....1..0..0....1..0..0
..0..0..0....0..0..1....0..0..0....1..1..0....1..0..0....0..1..0....1..0..1
..1..0..1....0..1..0....1..0..1....0..1..0....0..1..0....1..0..1....0..1..0
..0..1..0....1..0..1....0..1..0....1..0..1....1..0..1....0..1..0....0..0..1
..1..0..0....0..1..0....0..0..1....0..0..1....0..0..0....1..0..1....1..1..0
..0..1..0....1..0..0....0..1..0....1..0..0....1..0..0....0..0..0....1..0..1
CROSSREFS
Column 1 of A260927.
Sequence in context: A348274 A033701 A349869 * A132956 A260015 A163244
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 04 2015
STATUS
approved

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Last modified April 15 05:45 EDT 2024. Contains 371667 sequences. (Running on oeis4.)