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A125709 Number of n-indecomposable polyominoes with at least n cells. 6
1, 5, 32, 444, 13375, 684215, 52267513 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A polyomino is called n-indecomposable if it cannot be partitioned (along cell boundaries) into two or more polyominoes each with at least n cells.

MacKinnon incorrectly gives a(3) = 42.

For full lists of drawings of these polyominoes for n <= 6, see the links in A125759.

REFERENCES

N. MacKinnon, Some thoughts on polyomino tilings, Math. Gaz., 74 (1990), 31-33.

Rinaldi, Simone, and D. G. Rogers. "Indecomposability: polyominoes and polyomino tilings." The Mathematical Gazette 92.524 (2008): 193-204.

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

The five 2-indecomposable polyominoes:

...................X.

XX..XXX..XX..XXX..XXX

..........X...X....X.

CROSSREFS

Row sums of A125753. Cf. A125759, A125761, A126742, A126743.

Sequence in context: A185136 A014374 A185336 * A203112 A174471 A275233

Adjacent sequences:  A125706 A125707 A125708 * A125710 A125711 A125712

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Feb 01 2007

EXTENSIONS

a(4) and a(5) from Peter Pleasants, Feb 13 2007

a(6) and a(7) from David Applegate, Feb 16 2007

STATUS

approved

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Last modified April 24 16:26 EDT 2019. Contains 322430 sequences. (Running on oeis4.)