A221394 Number of n X 3 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, with every occupancy equal to zero or two.

0, 18, 0, 631, 0, 23188, 0, 852298, 0, 31322020, 0, 1151041183, 0, 42298797564, 0, 1554405335830, 0, 57121595318958, 0, 2099115475346705, 0, 77138701114715724, 0, 2834707878337590102, 0, 104170392148337357776, 0, 3828073672066667898151, 0

Offset

1,2

Comments

Column 3 of A221396.

Links

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

Formula

Empirical: a(n) = 48*a(n-2) - 440*a(n-4) + 998*a(n-6) - 873*a(n-8) + 252*a(n-10) + 16*a(n-12).

Empirical g.f.: x^2*(18 - 233*x^2 + 820*x^4 - 1050*x^6 + 412*x^8 + 46*x^10) / ((1 - x)*(1 + x)*(1 - 47*x^2 + 393*x^4 - 605*x^6 + 268*x^8 + 16*x^10)). - Colin Barker, Aug 05 2018

Crossrefs

Cf. A221396.

Sequence in context: A335187 A231962 A052441 * A025602 A088126 A040327

Adjacent sequences: A221391 A221392 A221393 * A221395 A221396 A221397

Keyword

nonn

Author

R. H. Hardin, Jan 14 2013

Status

approved