

A006736


Series for first parallel moment of hexagonal lattice.
(Formerly M3597)


4



0, 4, 24, 104, 384, 1284, 4012, 11924, 34100, 94584, 255852, 677850, 1764482, 4523924, 11447870, 28636218, 70907326, 173991368, 423469988, 1023162920, 2455645268, 5858183260, 13898041838, 32804047708, 77067740230
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OFFSET

0,2


COMMENTS

The hexagonal lattice is the familiar 2dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.


REFERENCES

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


LINKS

I. Jensen, Table of n, a(n) for n = 0..90 (from link below)
J. W. Essam, A. J. Guttmann and K. De'Bell, On twodimensional directed percolation, J. Phys. A 21 (1988), 38153832.
I. Jensen, More terms
Iwan Jensen, Anthony J. Guttmann, Series expansions of the percolation probability for directed square and honeycomb lattices, arXiv:condmat/9509121, 1995; J. Phys. A 28 (1995), no. 17, 48134833.
G. Nebe and N. J. A. Sloane, Home page for hexagonal (or triangular) lattice A2


CROSSREFS

Cf. A006803, A006809, A006737.
Sequence in context: A048806 A043009 A355798 * A165752 A166036 A120908
Adjacent sequences: A006733 A006734 A006735 * A006737 A006738 A006739


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Simon Plouffe


STATUS

approved



