A056625 a(n) is the total area of all self-avoiding polygons of length 2n on the square lattice.

1, 4, 22, 124, 726, 4352, 26614, 165204, 1037672, 6580424, 42062040, 270661328, 1751614248, 11391756176, 74406502814, 487838450116, 3209229661682, 21175301453040, 140097533633112, 929160187609096

Offset: 2

Author

N. J. A. Sloane, Aug 30 2000

Keywords

• nonn

Links

• I. Jensen, Table of n, a(n) for n = 2..43 (from link below)
• I. Jensen, More terms

Crossrefs

Cf. A002931, A056631.

Extensions

Title clarified by Sean A. Irvine, Apr 25 2022