login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A029681
Theta series of quadratic form with Gram matrix [ 2, 1, 0; 1, 2, 1; 0, 1, 3 ].
2
1, 0, 6, 6, 0, 6, 6, 12, 6, 0, 6, 12, 6, 6, 24, 12, 0, 0, 18, 6, 6, 14, 12, 24, 6, 0, 18, 24, 12, 12, 12, 12, 6, 0, 12, 42, 0, 12, 30, 12, 6, 0, 42, 12, 12, 18, 12, 36, 6, 0, 30, 12, 6, 24, 24, 12, 24, 0, 24, 30, 12, 6, 36, 60, 0, 0, 12, 24, 0, 12, 42, 36, 18, 0, 24, 30, 6, 48, 36, 12, 6, 0, 24
OFFSET
0,3
COMMENTS
The Gram matrix [ 2, 1, 1; 1, 2, 1; 1, 1, 3 ] defines the same lattice.
This is the trigonal R lattice (the classical holotype) of dimension 3.
LINKS
G. Nebe and N. J. A. Sloane, Home page for this lattice
EXAMPLE
1 + 6*q^2 + 6*q^3 + 6*q^5 + 6*q^6 + 12*q^7 + 6*q^8 + 6*q^10 + 12*q^11 + 6*q^12 + ...
CROSSREFS
Sequence in context: A272648 A212708 A028969 * A109917 A153629 A154155
KEYWORD
nonn
AUTHOR
STATUS
approved