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A005400 High temperature series for spin-1/2 Heisenberg specific heat on 2D hexagonal lattice.
(Formerly M4603)
0, 9, 18, -306, -3240, 49176, 1466640, -13626000, -1172668032, 75256704, 1392243773184, 18426692664576, -2213592367094784 (list; graph; refs; listen; history; text; internal format)



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=1..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.

Index entries for sequences related to specific heat


Cf. A005399, A005402.

Sequence in context: A278588 A133361 A353183 * A134115 A071587 A061750

Adjacent sequences:  A005397 A005398 A005399 * A005401 A005402 A005403




N. J. A. Sloane


Better description from Steven Finch

a(11)-a(12) added from Oitmaa and Bornilla by Andrey Zabolotskiy, Oct 20 2021

a(13) from Elstner et al. (see table I; signs differ because they consider antiferromagnet, and they mention energy instead of specific heat because the same coefficients are involved, cf. Eqs. (11) and (13) from Oitmaa & Bornilla) added by Andrey Zabolotskiy, Jun 17 2022



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Last modified July 5 23:40 EDT 2022. Contains 355108 sequences. (Running on oeis4.)