A207044 Number of (n+1) X 3 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly one clockwise edge increases.

150, 270, 552, 1182, 2244, 4722, 9582, 18930, 39348, 78804, 159042, 325836, 653826, 1328730, 2698986, 5441712, 11061960, 22395798, 45304764, 91960698, 186084846, 376987458, 764272620, 1547133684, 3135436986, 6352558164, 12865282314

Offset

1,1

Comments

Column 2 of A207050.

Links

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

Formula

Empirical: a(n) = 2*a(n-2) + 5*a(n-3) - a(n-4) - a(n-5) for n>7.

Empirical g.f.: 6*x*(25 + 45*x + 42*x^2 - 18*x^3 - 10*x^4 + 3*x^5 + x^6) / (1 - 2*x^2 - 5*x^3 + x^4 + x^5). - Colin Barker, Jun 17 2018

Example

Some solutions for n=4:
  2 2 0    1 2 2    1 0 2    1 2 2    2 0 0    0 1 1    0 1 1
  2 0 0    2 2 2    1 1 2    2 2 2    2 2 0    0 1 1    1 1 1
  2 0 0    2 2 1    1 1 1    2 2 0    2 2 2    0 0 1    1 1 0
  2 2 0    2 0 0    0 1 1    2 0 0    1 2 2    0 0 0    1 2 2
  2 2 2    2 0 0    0 0 0    0 0 0    1 1 2    1 0 0    1 2 2

Crossrefs

Cf. A207050.

Sequence in context: A116185 A008889 A184075 * A292705 A335145 A063829

Adjacent sequences: A207041 A207042 A207043 * A207045 A207046 A207047

Keyword

nonn

Author

R. H. Hardin, Feb 14 2012

Status

approved