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A056634
Number of polygons of length 2n with one hole on square lattice (not allowing rotations).
3
1, 24, 342, 3804, 36802, 326540, 2735308, 22006264, 171912401, 1313614776, 9868281330, 73150450248, 536495354621, 3900954906412, 28164962681150, 202166363020920, 1444068530799525, 10272599729628876
OFFSET
8,2
LINKS
I. Jensen, Table of n, a(n) for n = 8..41 (from link below)
I. Jensen, More terms
CROSSREFS
Cf. A002931.
Sequence in context: A264454 A077527 A083766 * A022748 A288968 A269029
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 30 2000
STATUS
approved