

A125709


Number of nindecomposable polyominoes with at least n cells.


6




OFFSET

1,2


COMMENTS

A polyomino is called nindecomposable 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), 3133.
Rinaldi, Simone, and D. G. Rogers. "Indecomposability: polyominoes and polyomino tilings." The Mathematical Gazette 92.524 (2008): 193204.


LINKS

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


EXAMPLE

The five 2indecomposable 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



