A221189 Number of n X 2 arrays of occupancy after each element moves to some king-move neighbor.

1, 31, 318, 3605, 39851, 441912, 4896043, 54248371, 601050906, 6659404865, 73783381595, 817488259440, 9057417947527, 100352286120727, 1111860046543146, 12318929680916909, 136488426454208783, 1512232882805726640

Offset

1,2

Comments

Column 2 of A221192.

Links

R. H. Hardin, Table of n, a(n) for n = 1..20

Formula

Empirical: a(n) = 15*a(n-1) - 41*a(n-2) - 42*a(n-3) + 174*a(n-4) - 86*a(n-5) - 2*a(n-6).

Empirical g.f.: x*(1 + 16*x - 106*x^2 + 148*x^3 - 58*x^4) / (1 - 15*x + 41*x^2 + 42*x^3 - 174*x^4 + 86*x^5 + 2*x^6). - Colin Barker, Mar 14 2018

Example

Some solutions for n=3:
..0..0....0..2....1..1....2..2....0..0....1..0....0..0....0..2....0..1....2..0
..1..3....0..1....0..1....0..1....1..1....1..2....2..0....2..1....4..0....2..0
..1..1....2..1....3..0....0..1....2..2....1..1....1..3....1..0....0..1....0..2

Crossrefs

Cf. A221192.

Sequence in context: A142382 A137318 A182025 * A362493 A029813 A138697

Adjacent sequences: A221186 A221187 A221188 * A221190 A221191 A221192

Keyword

nonn

Author

R. H. Hardin, Jan 04 2013

Status

approved