A002907 High temperature series in v = tanh(J/kT) for residual correlation function (correction to susceptibility) for the spin-1/2 Ising model on square lattice.

2, 2, 20, 38, 146, 368, 1070, 2824, 7680, 19996, 53024, 136350, 355254, 906254, 2331416, 5909810, 15067236, 37992680, 96210436, 241564514, 608469654, 1522388638, 3818281784, 9525139886, 23806217352, 59237754234, 147621207142, 366533832540, 911151508282

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Comments

Previous name was: Susceptibility for square lattice.

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• M. F. Sykes and M. E. Fisher, Antiferromagnetic susceptibility of the plane square and honeycomb Ising lattices, Physica, 28 (1962), 919-938.

Crossrefs

Cf. A002906, A002908.

Formula

G.f.: ((1-3*v)^2*xi(v) - (1-v)^2 + 2*v*u(v)) / (8*v^7*(1+v)^2), where xi(v) is the g.f. of A002906 and u(v) is the g.f. of A002908 (odd powers only!); the actual "residual correlation function" is the numerator of this expression [Sykes & Fisher]. - Andrey Zabolotskiy, Feb 28 2021

Extensions

New name and terms a(10) and beyond from Andrey Zabolotskiy, Feb 28 2021