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.

A217511 Theta series of hexagonal diamond or Lonsdaleite net with respect to an atom.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 1, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 6, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 18
Offset: 0

Views

Author

N. J. A. Sloane, Oct 05 2012

Keywords

Comments

Eq. (20) of [Sloane, 1987] gives the g.f. of this sequence if one replaces the binomial in the round brackets with the factor eta_{3/8}(X^(16/3)); this error propagated from Eq. (67) of [Sloane & Teo, 1985], where the second curly brackets should be replaced by psi_{8/3}(q^(16/3)) to get the g.f. of A005873 (or, alternatively, replace the power 4/3 with 1/3 in both formulas). - Andrey Zabolotskiy, Jun 04 2022

Crossrefs

Formula

a(n) = A004012(n/8) + A005873(n), where the 1st term is 0 unless 8|n. - Andrey Zabolotskiy, Jun 03 2022

Extensions

Missing a(71) = 0 inserted by Andrey Zabolotskiy, Jun 03 2022

A008524 Coordination sequence for 4-dimensional lonsdaleite (or wurtzite).

Original entry on oeis.org

1, 5, 20, 53, 116, 213, 360, 561, 832, 1171, 1600
Offset: 0

Views

Author

Keywords

References

  • M. O'Keeffe, N-dimensional diamond, sodalite and rare sphere packings, Acta Cryst., A 47 (1991), 749-753.

Crossrefs

For 3-D see A008264. Cf. A008525 etc.

Extensions

Missing a(1)=5 inserted by Sean A. Irvine, Oct 17 2020
Showing 1-2 of 2 results.