A359520 Number of free holey polyominoes of n cells with simply-connected interiors.

0, 0, 0, 0, 0, 0, 1, 5, 35, 179, 909, 4285, 19702, 88040, 386826, 1674852, 7174436, 30462009

Offset

1,8

Links

Table of n, a(n) for n=1..18.

Formula

a(n) = A342537(n) - A000104(n) (simply connected polyominoes minus unholey polyominoes).

Example

a(7) = 1 because of the holey heptomino.

Crossrefs

Cf. A000104, A000105, A001419, A342537, A359519.

Sequence in context: A219973 A100739 A329762 * A376496 A043014 A165755

Adjacent sequences: A359517 A359518 A359519 * A359521 A359522 A359523

Keyword

nonn,more

Author

John Mason, Jan 04 2023

Status

approved