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A003202 Cluster series for hexagonal lattice.
(Formerly M4117)
0
1, 6, 18, 48, 126, 300, 750, 1686, 4074, 8868 (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

J. W. Essam, Percolation and cluster size, in C. Domb and M. S. Green, Phase Transitions and Critical Phenomena, Ac. Press 1972, Vol. 2; see especially pp. 225-226.

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

M. F. Sykes and J. W. Essam, Critical percolation probabilities by series methods, Phys. Rev., 133 (1964), A310-A315.

LINKS

Table of n, a(n) for n=0..9.

G. Nebe and N. J. A. Sloane, Home page for hexagonal (or triangular) lattice A2

CROSSREFS

Sequence in context: A248462 A256010 A128543 * A003198 A099857 A163765

Adjacent sequences:  A003199 A003200 A003201 * A003203 A003204 A003205

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified December 14 14:50 EST 2019. Contains 329979 sequences. (Running on oeis4.)