A357647 a(n) is the number of free unholey polyominoes of n cells with 90-degree rotational symmetry and no other.

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 2, 0, 0, 7, 7, 0, 0, 22, 24, 0, 0, 71, 82, 0, 0, 239, 280, 0, 0, 817, 970, 0, 0, 2841, 3403, 0, 0, 10027, 12064, 0, 0, 35800, 43193, 0, 0, 129007, 156011, 0, 0, 468541, 567664, 0, 0, 1713174

Offset

1,12

Links

Table of n, a(n) for n=1..56.

Crossrefs

Cf. A000104, A144553.

Sequence in context: A121178 A175917 A320525 * A069971 A167291 A063865

Adjacent sequences: A357644 A357645 A357646 * A357648 A357649 A357650

Keyword

nonn

Author

John Mason, Oct 10 2022

Status

approved