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A005399 E.g.f.: high-temperature series in J/2kT for ferromagnetic susceptibility for the spin-1/2 Heisenberg model on hexagonal lattice.
(Formerly M4256)
1, 6, 48, 408, 3600, 42336, 781728, 13646016, 90893568, -1798204416, 70794720768, 7538546211840, 63813109782528, -12977417912045568 (list; graph; refs; listen; history; text; internal format)



Previous name was: Susceptibility series for hexagonal lattice.

The hexagonal lattice is the familiar 2-dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.


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


Table of n, a(n) for n=0..13.

G. A. Baker Jr., H. E. Gilbert, J. Eve, and G. S. Rushbrooke, On the two-dimensional, spin-1/2 Heisenberg ferromagnetic models, Phys. Lett., 25A (1967), 207-209.

N. Elstner, R. R. P. Singh and A. P. Young, Finite temperature properties of the spin-1/2 Heisenberg antiferromagnet on the triangular lattice, Phys. Rev. Lett., 71 (1993), 1629-1632.

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

J. Oitmaa and E. Bornilla, High-temperature-series study of the spin-1/2 Heisenberg ferromagnet, Phys. Rev. B, 53 (1996), 14228.


Cf. A002920, A047709, A005400, A005401, A005402.

Sequence in context: A264083 A083233 A002918 * A258790 A345077 A244038

Adjacent sequences:  A005396 A005397 A005398 * A005400 A005401 A005402




N. J. A. Sloane


New name from Andrey Zabolotskiy, Mar 03 2021

a(10)-a(12) added from Oitmaa and Bornilla by Andrey Zabolotskiy, Oct 20 2021

a(0) and a(13) using data from Elstner et al. (see Table I for the values -(-1)^n*n*a(n-1)) added by Andrey Zabolotskiy, Jun 17 2022



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Last modified June 30 12:59 EDT 2022. Contains 354939 sequences. (Running on oeis4.)