

A006739


Site percolation series for hexagonal lattice.
(Formerly M2654)


2



1, 3, 7, 15, 31, 62, 122, 235, 448, 842, 1572, 2904, 5341, 9743, 17718, 32009, 57701, 103445, 185165, 329904, 587136, 1040674, 1843300, 3253020, 5738329, 10090036, 17736533, 31086416, 54484239, 95220744, 166451010, 290209573
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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..82 (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

Sequence in context: A034480 A218281 A057703 * A119407 A224521 A269167
Adjacent sequences: A006736 A006737 A006738 * A006740 A006741 A006742


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Simon Plouffe


STATUS

approved



