

A006738


Series for second perpendicular moment of hexagonal lattice.
(Formerly M2024)


2



0, 2, 12, 54, 206, 712, 2294, 7024, 20656, 58842, 163250, 443062, 1180156, 3092964, 7993116, 20401250, 51502616, 128748512, 319010540, 784179992, 1913668608, 4639155964, 11178566462, 26784974870, 63851541584
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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)
I. G. Enting, A, J. Guttmann and I. Jensen, LowTemperature Series Expansions for the Spin1 Ising Model, arXiv:heplat/9410005, 1994; J. Phys. A. 27 (1994) 69877006.
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, A006736, A006737.
Sequence in context: A036359 A055703 A242513 * A212697 A111642 A145766
Adjacent sequences: A006735 A006736 A006737 * A006739 A006740 A006741


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Simon Plouffe


STATUS

approved



