%I M4603
%S 0,9,18,306,3240,49176,1466640,13626000,1172668032,75256704
%N High temperature series for spin1/2 Heisenberg specific heat on 2D hexagonal lattice.
%C The hexagonal lattice is the familiar 2dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.
%D G. A. Baker et al., On the twodimensional, spin1/2 Heisenberg ferromagnetic models, Phys. Lett., 25A (1967), 207209.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H G. Nebe and N. J. A. Sloane, <a href="http://www.math.rwthaachen.de/~Gabriele.Nebe/LATTICES/A2.html">Home page for hexagonal (or triangular) lattice A2</a>
%H <a href="/index/Sp#specific_heat">Index entries for sequences related to specific heat</a>
%K sign
%O 1,2
%A _N. J. A. Sloane_.
%E Better description from _Steven Finch_
