A057409 Number of self-avoiding polygons of area n with any number of (self-avoiding polygon) holes on square lattice (not allowing rotations).

1, 2, 6, 19, 63, 216, 756, 2685, 9650, 35018, 128084, 471623, 1746492, 6499356, 24290272, 91123171, 342984175, 1294829776, 4901319978, 18597856445, 70723784744, 269486503694, 1028736811230, 3933715966653

Offset: 1

Author

N. J. A. Sloane, Aug 30 2000

Keywords

• nonn

Links

• I. Jensen, Table of n, a(n) for n = 1..40 (from link below)
• Anthony J. Guttmann, Iwan Jensen and Aleksander L. Owczarek, Polygonal polyominoes on the square lattice, J. Phys. A: Math. Gen., 34 (2001), 3721-3733.
• I. Jensen, More terms

Crossrefs

Cf. A006724 (no holes, first differs at n=8), A057406, A057407, A057408 (resp. 1, 2, 3 holes); A001168 (any holes, first differs at n=7); A088702 (by perimeter); A000104 (no holes, rotations and reflections allowed).