

A006803


Percolation series for hexagonal lattice.
(Formerly M2232)


5



1, 0, 0, 1, 0, 3, 1, 9, 6, 29, 27, 99, 112, 351, 450, 1275, 1782, 4704, 6998, 17531, 27324, 65758, 106211, 247669, 411291, 935107, 1587391, 3535398, 6108103, 13373929, 23438144, 50592067, 89703467, 191306745, 342473589
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OFFSET

0,6


COMMENTS

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


REFERENCES

J. Blease, Series expansions for the directedbond percolation problem, J. Phys. C 10 (1977), 917924.
J. W. Essam, A. J. Guttmann and K. De'Bell, On twodimensional directed percolation, J. Phys. A 21 (1988), 38153832.
Jensen, Iwan; Guttmann, Anthony J.; Series expansions of the percolation probability for directed square and honeycomb lattices. J. Phys. A 28 (1995), no. 17, 48134833.
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..51
I. Jensen, More terms
G. Nebe and N. J. A. Sloane, Home page for hexagonal (or triangular) lattice A2


CROSSREFS

Cf. A006809.
Sequence in context: A229759 A185580 A052931 * A197730 A231902 A143495
Adjacent sequences: A006800 A006801 A006802 * A006804 A006805 A006806


KEYWORD

sign


AUTHOR

N. J. A. Sloane


STATUS

approved



