

A006741


Series for second parallel moment of hexagonal lattice.
(Formerly M4269)


1



0, 6, 60, 314, 1240, 4166, 12600, 35324, 93576, 236944, 578764, 1371478, 3169380, 7165478, 15901324, 34705018, 74661832, 158529158, 332756408, 691084378, 1421836528, 2899678894, 5867341452, 11784640984, 23512608484
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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)
I. G. Enting, A, J. Guttmann and I. Jensen, LowTemperature Series Expansions for the Spin1 Ising Model, J. Phys. A. 27 (1994) 69877006.
J. W. Essam, A. J. Guttmann and K. De'Bell, On twodimensional directed percolation, arXiv:heplat/9410005, 1994; 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: A296317 A292061 A074441 * A120573 A260345 A028244
Adjacent sequences: A006738 A006739 A006740 * A006742 A006743 A006744


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Simon Plouffe


STATUS

approved



