A006725 Number of n-celled polygons with perimeter 2n+2 on square lattice.

1, 2, 6, 18, 55, 174, 566, 1868, 6237, 21050, 71666, 245696, 847317, 2937116, 10226574, 35746292, 125380257, 441125966, 1556301578, 18155586993

Offset: 1

Author

N. J. A. Sloane, Simon Plouffe

Keywords

• nonn

References

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

Links

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

Extensions

Title corrected by David Bevan, Sep 28 2011