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 1-2 of 2 results.

A005399 E.g.f.: high-temperature series in J/2kT for ferromagnetic susceptibility for the spin-1/2 Heisenberg model on hexagonal lattice.

Original entry on oeis.org

1, 6, 48, 408, 3600, 42336, 781728, 13646016, 90893568, -1798204416, 70794720768, 7538546211840, 63813109782528, -12977417912045568, -320549902414196736, 33016479733605777408, 1709506241695601983488
Offset: 0

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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.

References

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

Crossrefs

Cf. A002920 (Ising high-temperature), A047709 (Ising low-temperature), A005400 (series for specific heat, or free energy), A005401 (square lattice), A005402 (specific heat for square lattice).

Extensions

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
a(14)-a(16) using Pierre, Bernu & Messio's data added by Andrey Zabolotskiy, Nov 25 2024

A005402 High temperature series for spin-1/2 Heisenberg specific heat on 2D square lattice.

Original entry on oeis.org

0, 6, -12, -84, 1200, 3120, -249312, 920928, 86274816, -1232035584, -40970012160, 1391730516480, 20983074318336, -1798371774277632, -1850681724997632, 2713439169345073152, -40045819902128750592, -4625352042615223025664, 171173842584165886328832, 8223835353617664214695936
Offset: 1

Views

Author

Keywords

References

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

Crossrefs

Cf. A005400 (hexagonal), A002169 (cubic); A005401 (susceptibility).

Extensions

Better description from Steven Finch
a(11)-a(14) added from Oitmaa and Bornilla by Andrey Zabolotskiy, Oct 20 2021 and Feb 05 2022
Terms a(15) and beyond from Pierre, Bernu & Messio added by Andrey Zabolotskiy, Nov 18 2024
Showing 1-2 of 2 results.