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A206199 Number of (n+1) X 2 0..3 arrays with every 2 X 3 or 3 X 2 subblock having exactly one clockwise edge increases. 1
256, 480, 1768, 7388, 29724, 117084, 468968, 1878808, 7493008, 29925508, 119605588, 477741796, 1908251600, 7623408272, 30453658424, 121651754668, 485967430220, 1941313945708, 7755000190904, 30979095429960, 123753089725152 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 1 of A206206.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) + 17*a(n-3) - 5*a(n-4) + 2*a(n-5) for n>6.
Empirical g.f.: 4*x*(64 - 72*x + 82*x^2 - 567*x^3 + 170*x^4 - 64*x^5) / (1 - 3*x - 17*x^3 + 5*x^4 - 2*x^5). - Colin Barker, Jun 14 2018
EXAMPLE
Some solutions for n=4:
1 3 1 2 2 0 1 1 0 2 1 3 1 0 3 3 1 0 2 2
1 1 1 2 2 2 1 3 0 0 2 2 0 0 1 1 0 0 1 1
1 1 1 2 2 2 3 3 0 0 2 2 0 0 1 1 0 0 1 1
3 0 1 1 0 0 3 3 1 0 2 0 0 2 2 3 1 2 2 0
3 3 1 1 0 0 2 2 1 0 2 3 1 1 2 2 1 1 3 3
CROSSREFS
Cf. A206206.
Sequence in context: A223693 A223064 A206206 * A271811 A255998 A309092
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 04 2012
STATUS
approved

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Last modified April 17 04:44 EDT 2024. Contains 371756 sequences. (Running on oeis4.)