A221266 Number of n X 2 arrays of occupancy after each element stays put or moves to some king-move neighbor, with no occupancy greater than 2.

3, 19, 141, 1073, 8203, 62771, 480437, 3677345, 28147315, 215447091, 1649090685, 12622590641, 96616760123, 739531104531, 5660573328101, 43327576375905, 331641119361379, 2538471829096403, 19430157634105069, 148723740543110065

Offset

1,1

Comments

Column 2 of A221269.

Links

R. H. Hardin, Table of n, a(n) for n = 1..66

Formula

Empirical: a(n) = 10*a(n-1) - 19*a(n-2) + 8*a(n-3).

Empirical g.f.: x*(1 - x)*(3 - 8*x) / (1 - 10*x + 19*x^2 - 8*x^3). - Colin Barker, Aug 04 2018

Example

Some solutions for n=3:
  0 2   2 1   1 2   2 0   0 2   1 2   0 2   1 2   2 0   1 1
  2 0   0 0   0 1   2 1   0 2   1 0   1 1   1 0   2 2   1 0
  1 1   1 2   0 2   1 0   2 0   2 0   0 2   1 1   0 0   2 1

Crossrefs

Cf. A221269.

Sequence in context: A074559 A027314 A025571 * A082758 A110525 A331716

Adjacent sequences: A221263 A221264 A221265 * A221267 A221268 A221269

Keyword

nonn

Author

R. H. Hardin, Jan 08 2013

Status

approved