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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The hexagonal lattice is the familiar 2-dimensional 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 two-dimensional directed percolation, J. Phys. A 21 (1988), 3815-3832.

I. Jensen, More terms

Iwan Jensen, Anthony J. Guttmann, Series expansions of the percolation probability for directed square and honeycomb lattices, arXiv:cond-mat/9509121, 1995; J. Phys. A 28 (1995), no. 17, 4813-4833.

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

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Last modified August 13 08:34 EDT 2020. Contains 336442 sequences. (Running on oeis4.)