A056639 Number of polygons of length 2n with 3 (self-avoiding polygon) holes on square lattice (not allowing rotations).

62, 3920, 130560, 3058544, 56925214, 900355884, 12619939046, 161208191596, 1913821820768, 21416926011756, 228320059956022, 2337581305737496, 23128907576991302, 222266054948571020, 2082868947950189248

Offset: 16

Author

N. J. A. Sloane, Aug 30 2000

Keywords

• nonn

Links

• I. Jensen, Table of n, a(n) for n = 16..45 (from link below)
• I. Jensen, More terms

Crossrefs

Cf. A002931.