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A206200 Number of (n+1) X 3 0..3 arrays with every 2 X 3 or 3 X 2 subblock having exactly one clockwise edge increases. 1
480, 1060, 3008, 9464, 22576, 67968, 192808, 496088, 1475768, 4018720, 10894120, 31512000, 85274000, 237162184, 670298216, 1827175160, 5121768064, 14281894072, 39288809968, 110061644032, 305182278280, 845001830872, 2359774258680 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A206206.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-2) + 14*a(n-3) - 3*a(n-4) + a(n-5) + a(n-6) + a(n-7) for n > 9.
Empirical g.f.: 4*x*(120 + 265*x + 392*x^2 - 109*x^3 + 38*x^4 + 41*x^5 + 17*x^6 - 9*x^7 - 3*x^8) / (1 - 3*x^2 - 14*x^3 + 3*x^4 - x^5 - x^6 - x^7). - Colin Barker, Jun 14 2018
EXAMPLE
Some solutions for n=4:
0 0 1 1 2 2 3 0 0 1 0 2 3 0 0 0 3 3 0 1 1
0 0 1 2 2 2 3 3 0 1 2 2 3 3 0 3 3 3 1 1 1
0 1 1 2 2 3 3 3 3 1 2 2 3 3 3 3 3 0 1 1 2
0 1 1 2 3 3 1 3 3 1 1 2 2 3 3 3 0 0 1 2 2
0 0 1 2 3 3 1 1 3 1 1 2 2 2 2 3 0 0 1 2 2
CROSSREFS
Cf. A206206.
Sequence in context: A179667 A108876 A293187 * A258558 A083728 A199808
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 04 2012
STATUS
approved

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Last modified April 15 05:06 EDT 2024. Contains 371667 sequences. (Running on oeis4.)