A005880 Theta series of D_4 lattice with respect to edge.

2, 8, 12, 16, 26, 24, 28, 48, 36, 40, 64, 48, 62, 80, 60, 64, 96, 96, 76, 112, 84, 88, 156, 96, 114, 144, 108, 144, 160, 120, 124, 208, 168, 136, 192, 144, 148, 248, 192, 160, 242, 168, 216, 240

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..5000
• Index entries for sequences related to D_4 lattice

Crossrefs

Equals 2 * A008438.

Programs

Mathematica

Table[2 DivisorSigma[1, 2 n + 1], {n, 0, 43}] (* Jean-François Alcover, Jul 06 2017 *)

PARI

for(n=0, 30, print1(2*sigma(2*n+1), ", ")) \\ G. C. Greubel, Nov 30 2017