A245660 Number of unitary polyominoes without holes with n cells. A unitary polyomino is a polyomino whose edges all have length 1.

1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 2, 1, 2, 4, 5, 4, 12, 13, 20, 29, 52, 67, 106, 173, 269, 375, 658, 991, 1512, 2425, 3896, 5902, 9454, 15146, 23601, 37050, 59908, 93777, 148151, 237228, 375893, 593773, 948623, 1508823, 2393035, 3812023, 6083290, 9666024, 15404085, 24592209

Offset

1,11

Links

Table of n, a(n) for n=1..50.

John Mason, Counting unitary polyominoes without holes

George Sicherman, Catalogue of Unitary Polyominoes

Crossrefs

Cf. A245620, number of unitary polyominoes with n cells.

Sequence in context: A057061 A074807 A307729 * A034804 A050042 A166578

Adjacent sequences: A245657 A245658 A245659 * A245661 A245662 A245663

Keyword

nonn,hard,more

Author

Joerg Arndt, Jul 28 2014

Extensions

Added a(16)-a(20), George Sicherman, Jul 29 2014

a(21)-a(43) from John Mason, Apr 21 2023

a(44)-a(50) from John Mason, Apr 26 2023

Status

approved