A029821 Average theta series of odd unimodular lattices of dimension 20 (multiplied by 31).

31, 8, 4104, 157472, 2093064, 15625008, 80783136, 322828864, 1071640584, 3099521384, 8015629104, 18863581536, 41199871776, 84835994992, 165611207232, 307562657472, 548679970824, 948703011984, 1590054469992, 2581501582240

Offset

0,1

Links

Table of n, a(n) for n=0..19.

Prog

(PARI) a(n)=if(n<1, 31*(n==0), 8*(sigma(n, 9)-if(n%4==0, 1024*sigma(n/4, 9)))) /* Michael Somos, Jul 16 2004 */

Crossrefs

Sequence in context: A174129 A305663 A040936 * A040935 A145584 A178561

Adjacent sequences: A029818 A029819 A029820 * A029822 A029823 A029824

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved