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A162677 Number of different fixed (possibly) disconnected polyominoes (of any area) bounded (not necessarily tightly) by an n*n square. 5
1, 10, 400, 57856, 31522816, 66605547520, 554222579875840, 18303191835587117056, 2408425353007592768536576, 1265177138001297870205254369280, 2655861110791164560222750369099284480 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = 2^(n^2)-2*2^((n-1)*n)+2^((n-1)^2).
EXAMPLE
a(2)=10: the monomino, 4 dominoes (2 strictly disconnected), 4 rotations of the L tromino, and the square tetromino.
PROG
(PARI) a(n) = 2^(n^2) - 2*2^((n-1)*n) + 2^((n-1)^2); \\ Michel Marcus, Aug 30 2013
CROSSREFS
Sequence in context: A183487 A172505 A098722 * A041767 A130557 A231052
KEYWORD
nonn
AUTHOR
David Bevan, Jul 27 2009
STATUS
approved

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Last modified March 1 09:59 EST 2024. Contains 370432 sequences. (Running on oeis4.)