A162677 Number of different fixed (possibly) disconnected polyominoes (of any area) bounded (not necessarily tightly) by an n*n square.

1, 10, 400, 57856, 31522816, 66605547520, 554222579875840, 18303191835587117056, 2408425353007592768536576, 1265177138001297870205254369280, 2655861110791164560222750369099284480

Offset: 1

Author

David Bevan, Jul 27 2009

Keywords

• nonn

Examples

			a(2)=10: the monomino, 4 dominoes (2 strictly disconnected), 4 rotations of the L tromino, and the square tetromino.
		

Crossrefs

Cf. A162673, A162674, A162675, A162676.

Programs

PARI

a(n) = 2^(n^2) - 2*2^((n-1)*n) + 2^((n-1)^2); \\ Michel Marcus, Aug 30 2013

Formula

a(n) = 2^(n^2)-2*2^((n-1)*n)+2^((n-1)^2).