cp's OEIS Frontend

A006737 Series for second parallel moment of hexagonal lattice.

%I A006737 M4275 #22 Oct 04 2019 07:41:08
%S A006737 0,6,68,442,2218,9528,36834,131856,445000,1433294,4444006,13349510,
%T A006737 39041224,111583236,312618368,860662498,2333112020,6238124024,
%U A006737 16474149036,43023953304,111230237224,284926172100,723731637254
%N A006737 Series for second parallel moment of hexagonal lattice.
%C A006737 The hexagonal lattice is the familiar 2-dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.
%D A006737 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A006737 I. Jensen, <a href="/A006737/b006737.txt">Table of n, a(n) for n = 0..90</a> (from link below)
%H A006737 I. G. Enting, A, J. Guttmann and I. Jensen, <a href="https://arxiv.org/abs/hep-lat/9410005">Low-Temperature Series Expansions for the Spin-1 Ising Model</a>, arXiv:hep-lat/9410005, 1994; J. Phys. A. 27 (1994) 6987-7006.
%H A006737 J. W. Essam, A. J. Guttmann and K. De'Bell, <a href="https://doi.org/10.1088/0305-4470/21/19/018">On two-dimensional directed percolation</a>, J. Phys. A 21 (1988), 3815-3832.
%H A006737 I. Jensen, <a href="https://researchers.ms.unimelb.edu.au/~ij@unimelb/dirperc/series/triabond_t2.ser">More terms</a>
%H A006737 Iwan Jensen, Anthony J. Guttmann, <a href="https://arxiv.org/abs/cond-mat/9509121">Series expansions of the percolation probability for directed square and honeycomb lattices</a>, arXiv:cond-mat/9509121, 1995; J. Phys. A 28 (1995), no. 17, 4813-4833.
%H A006737 G. Nebe and N. J. A. Sloane, <a href="http://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/A2.html">Home page for hexagonal (or triangular) lattice A2</a>
%Y A006737 Cf. A006803, A006809, A006736, A006738.
%K A006737 nonn
%O A006737 0,2
%A A006737 _N. J. A. Sloane_, _Simon Plouffe_