A006726 Number of n-celled polygons with perimeter 2n on square lattice. (Formerly M4523)

1, 8, 40, 168, 676, 2672, 10376, 39824, 151878, 576656, 2181496, 8229160, 30974700, 116385088, 436678520, 1636472360, 6126647748, 22917705088, 85665656544, 320017226840, 1194831754000, 4458991029368, 16633655077292, 62027025386904, 231224661281354

Offset

4,2

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Andrei Zabolotskii, Table of n, a(n) for n = 4..50

I. G. Enting and A. J. Guttmann, On the area of square lattice polygons, J. Statist. Phys., 58 (1990), 475-484.

Iwan Jensen, Series Expansions for Self-Avoiding Polygons. See Number of SAP of given area and any perimeter.

Crossrefs

Cf. A008855.

Sequence in context: A396031 A217375 A113071 * A383737 A165665 A000760

Adjacent sequences: A006723 A006724 A006725 * A006727 A006728 A006729

Keyword

nonn

Author

N. J. A. Sloane, Simon Plouffe

Extensions

Terms a(21) onward from Jensen added by Andrei Zabolotskii, Sep 12 2025

Status

approved