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A057730 Number of polyominoes (A000105) with perimeter 2n. 8
0, 1, 1, 3, 6, 25, 86, 416, 1988, 10572 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Does this include polyominoes with holes? - Franklin T. Adams-Watters, Sep 12 2006. Answer from R. J. Mathar: Yes! See the illustrations in the links.

LINKS

Table of n, a(n) for n=1..10.

Andrew Clarke, Isometrical Polyominoes

Andrew Clarke, Picture from Andrew Clarke's page showing the polyominoes of perimeters 4, 6, 8 and 10.

Gordon Hamilton, Grade 3 area and perimeter activity

R. J. Mathar, Illustrating perimeter 14

R. J. Mathar, Illustrating perimeter 16

R. J. Mathar, Illustrating perimeter 18

CROSSREFS

Cf. A000105, A002931, A057753, A266549 (same, but holes not allowed).

Sequence in context: A148662 A148663 A266549 * A074432 A212650 A297572

Adjacent sequences:  A057727 A057728 A057729 * A057731 A057732 A057733

KEYWORD

nonn,nice,more

AUTHOR

N. J. A. Sloane, Oct 29 2000

EXTENSIONS

Additional comments from Barry Cipra, Jun 08 2004

Link updated by William Rex Marshall, Dec 16 2009

a(9)-a(10) added by Luca Petrone, Jan 08 2016

a(1)-a(9) confirmed by Bert Dobbelaere, Oct 19 2018

STATUS

approved

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Last modified February 26 12:33 EST 2020. Contains 332279 sequences. (Running on oeis4.)