

A001419


Number of ncelled polyominoes with holes.
(Formerly M4226 N1767)


8



0, 0, 0, 0, 0, 0, 1, 6, 37, 195, 979, 4663, 21474, 96496, 425449, 1849252, 7946380, 33840946, 143060339, 601165888, 2513617990, 10466220315, 43425174374, 179630865835, 741123699012, 3050860717372
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OFFSET

1,8


REFERENCES

S. W. Golomb, Polyominoes. Scribner's, NY, 1965; second edition ( Polyominoes: Puzzles, Packings, Problems and Patterns) Princeton Univ. Press, 1994.
Joseph S. Madachy, "Pentominoes  Some Solved and Unsolved Problems", J. Rec. Math., 2 (1969), 181188.
T. R. Parkin, L. J. Lander and D. R. Parkin, ``Polyomino enumeration results,'' SIAM Fall Meeting, Santa Barbara, California, 1967.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=1..26.
Joseph Myers, Polyomino tiling
R. C. Read, Contributions to the cell growth problem, Canad. J. Math., 14 (1962), 120.
Eric Weisstein's World of Mathematics, Polyomino.


FORMULA

a(n) >= A057418(n).  R. J. Mathar, Jun 15 2014


CROSSREFS

Cf. A000104, A000105.
Sequence in context: A056328 A156185 A057418 * A081152 A244618 A033116
Adjacent sequences: A001416 A001417 A001418 * A001420 A001421 A001422


KEYWORD

nonn,hard


AUTHOR

N. J. A. Sloane.


EXTENSIONS

More terms from Joseph Myers, May 05 2002
More terms from Joseph Myers, Nov 04 2003
a(24)a(26) from Joseph Myers, Nov 17 2010


STATUS

approved



