A056634 Number of polygons of length 2n with one hole on square lattice (not allowing rotations).

1, 24, 342, 3804, 36802, 326540, 2735308, 22006264, 171912401, 1313614776, 9868281330, 73150450248, 536495354621, 3900954906412, 28164962681150, 202166363020920, 1444068530799525, 10272599729628876

Offset: 8

Author

N. J. A. Sloane, Aug 30 2000

Keywords

• nonn

Links

• I. Jensen, Table of n, a(n) for n = 8..41 (from link below)
• I. Jensen, More terms

Crossrefs

Cf. A002931.