A005869 Theta series of b.c.c. lattice with respect to short edge.

2, 6, 6, 8, 12, 6, 12, 18, 6, 14, 18, 12, 18, 18, 12, 12, 30, 18, 14, 24, 6, 30, 30, 12, 24, 24, 18, 24, 30, 12, 26, 42, 24, 12, 30, 18, 24, 48, 18, 36, 24, 18, 36, 30, 24, 26, 48, 18, 30, 48, 12, 36, 54, 12, 24, 30, 36, 48, 42, 30, 24, 54, 18, 26, 36, 30, 54, 54, 18, 24

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

References

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

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• N. J. A. Sloane and B. K. Teo, Theta series and magic numbers for close-packed spherical clusters, J. Chem. Phys. 83 (1985) 6520-6534.
• Index entries for sequences related to b.c.c. lattice

Crossrefs

Cf. A008443. Equals A005886/2. Cf. A121055.

Programs

Mathematica

QP = QPochhammer; CoefficientList[2*(QP[q^2]^2/QP[q])^3 + O[q]^70, q] (* Jean-François Alcover, Jul 05 2017, after Michael Somos *)