A126202 Number of pointed polyominoes with n cells.

1, 1, 1, 4, 12, 46, 172, 689, 2763, 11241, 45706, 186346, 759375, 3095191, 12610825, 51370336, 209194923, 851712069, 3466881944

Offset

0,4

Comments

Number of pairs (P,C), where P is a polyomino with n cells (cf. A000105) and C runs through the orbit representatives of cells in P under the automorphism group of P.

Links

Table of n, a(n) for n=0..18.

Example

a(4) = 12: polyomino and number of orbits on points:
XXXX..XXX..XXX..XX...XX
......X.....X....XX..XX
(2)...(4)..(3)..(2)..(1): total 12

Crossrefs

Cf. A000105.

Sequence in context: A149370 A149371 A149372 * A149373 A259203 A151464

Adjacent sequences: A126199 A126200 A126201 * A126203 A126204 A126205

Keyword

nonn,nice,more

Author

David Applegate and N. J. A. Sloane, Mar 09 2007

Status

approved