cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A002927 Low temperature series for spin-1/2 Ising magnetic susceptibility on 2D square lattice.

Original entry on oeis.org

0, 0, 1, 8, 60, 416, 2791, 18296, 118016, 752008, 4746341, 29727472, 185016612, 1145415208, 7059265827, 43338407712, 265168691392, 1617656173824, 9842665771649, 59748291677832, 361933688520940, 2188328005246304, 13208464812265559, 79600379336505560, 479025509574159232
Offset: 0

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Comments

The zero-field susceptibility per spin is 4m^2/kT * Sum_{n >= 0} a(n) * u^n, where u = exp(-4J/kT). (m is the magnetic moment of a single spin; this factor may be present or absent depending on the precise definition of the susceptibility.) The b-file has been obtained from the series by Guttmann and Jensen via the substitution r = u/(1-u)^2 and dividing by 4. - Andrey Zabolotskiy, Feb 11 2022

References

  • C. Domb, Ising model, in Phase Transitions and Critical Phenomena, vol. 3, ed. C. Domb and M. S. Green, Academic Press, 1974; p. 421.
  • S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 391-406.
  • 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).

Crossrefs

Cf. A002906 (high-temperature), A002979 (antiferromagnetic susceptibility), A029872 (specific heat), A002928 (magnetization), A002890 (partition function), A047709 (hexagonal lattice), A002912 (honeycomb), A002926 (cubic lattice), A010115 (spin-1 Ising).

Formula

a(n) ~ c * n^(3/4) * (1 + sqrt(2))^(2*n), where c = 0.0187325517235678... - Vaclav Kotesovec, May 06 2024

Extensions

Corrections and updates from Steven Finch
a(0) = a(1) = 0 prepended, terms a(20) and beyond added by Andrey Zabolotskiy, Feb 10 2022

A002916 High temperature series for spin-1/2 Ising specific heat on 3-dimensional simple cubic lattice.

Original entry on oeis.org

3, 33, 564, 8976, 155124, 2791308, 51382068, 962178084, 18258531348, 350143322088, 6772382631732, 131922552534036, 2585198190891636, 50919899448451512, 1007393565758096820, 20007153991627682124, 398699967207692643924, 7969220499183448073760, 159718349893920279061428
Offset: 0

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Author

Keywords

References

  • S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 391-406.
  • 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).

Crossrefs

Equals 3*A001408.
Cf. A002917 (b.c.c.), A002918 (f.c.c.), A001393 (partition function), A010571 (internal energy), A002913 (susceptibility), A002169 (Heisenberg model), A029872 (square, low-temperature).

Programs

Formula

Sum_{n>=0} a(n) * v^(2*n) = (v^2-1) * (-q/2*f(v)^2 - (v^2-1) * f'(v)^2 + f(v) * (2*v*f'(v) + (v^2-1)*f''(v))) / f(v)^2, where f(v) = Sum_{n>=0} A001393(n) * v^(2*n) and q = 6 is the number of nearest neighbors. - Andrey Zabolotskiy, Feb 15 2022

Extensions

Corrections and updates from Steven Finch
Terms a(13) and beyond from Andrey Zabolotskiy, Feb 15 2022

A029873 Low temperature series for spin-1/2 Ising specific heat on 2D square lattice, multiplied by 4.

Original entry on oeis.org

64, 288, 1152, 4800, 21504, 101920, 502016, 2538432, 13078720, 68344672, 361128960, 1925388608, 10341942016, 55899303840, 303764754944, 1658373055808, 9090505778112, 50008894293216
Offset: 0

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Author

Keywords

References

  • S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 391-406.

Crossrefs

Cf. A029872.

Formula

a(n) ~ 8 * (1 + sqrt(2))^(2*n+4) / (Pi*n). - Vaclav Kotesovec, Apr 28 2024

A029874 Low temperature series for spin-1/2 Ising specific heat on 2D square lattice, divided by 8.

Original entry on oeis.org

2, 9, 36, 150, 672, 3185, 15688, 79326, 408710, 2135771, 11285280, 60168394, 323185688, 1746853245, 9492648592, 51824157994, 284078305566, 1562777946663
Offset: 0

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Author

Keywords

References

  • S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 391-406.

Crossrefs

Cf. A029872.

Formula

a(n) ~ (1 + sqrt(2))^(2*n+4) / (4*Pi*n). - Vaclav Kotesovec, Apr 28 2024
Showing 1-4 of 4 results.