A010039 High-temperature expansion of Ising model susceptibility chi_2 for square lattice.

1, 4, 24, 208, 2208, 28864, 440064, 7752448, 153604608, 3398247424, 82812002304, 2208100261888, 63835179614208, 1991789102301184, 66630050985836544, 2381273427126550528, 90474637735806763008, 3643995535114567942144, 154996077159081295478784, 6946094284451252292026368

Offset

0,2

Comments

It appears that a(n) is divisible by 2^n, and a(2n) is additionally divisible by 3. - Ralf Stephan, Aug 04 2013

Links

Table of n, a(n) for n=0..19.

Laurent Pierre, Bernard Bernu and Laura Messio, High temperature series expansions of S = 1/2 Heisenberg spin models: Algorithm to include the magnetic field with optimized complexity, SciPost Phys. 17, 105 (2024); arXiv:2404.02271 [cond-mat.str-el], 2024. See the supporting file SquareIsing_18_1.py; multiply pol1[1] by 2 to get this sequence.

M. Lüscher and P. Weisz, Application of the linked cluster expansion to the n-component phi^4 theory, Nuclear Physics B 300 (1988), 325-359.

Formula

E.g.f.: F(tanh(x)), where F(x) is the g.f. of A002906. - Andrey Zabolotskiy, Nov 19 2024

Crossrefs

Cf. A002906, A010040 (cubic), A010042 (mu_2), A010045 (chi_4), A005401 (Heisenberg).

Sequence in context: A241980 A368267 A297218 * A245407 A162314 A369723

Adjacent sequences: A010036 A010037 A010038 * A010040 A010041 A010042

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Name clarified, terms a(15) and beyond using data from A002906 added by Andrey Zabolotskiy, Nov 25 2024

Status

approved