A029673 Theta series of quadratic form with Gram matrix [ 2, 0, 1; 0, 4, 2; 1, 2, 4 ].

1, 2, 10, 4, 10, 2, 16, 4, 26, 10, 0, 12, 20, 4, 36, 0, 26, 12, 30, 4, 10, 8, 32, 20, 32, 2, 40, 16, 20, 20, 12, 8, 58, 8, 20, 0, 50, 12, 64, 16, 0, 16, 40, 12, 60, 6, 36, 20, 52, 14, 10, 16, 20, 28, 64, 4, 84, 16, 40, 20, 0, 12, 72, 20, 58, 0, 40, 12, 60, 16, 16, 32, 78, 12, 80, 4, 20

Offset

0,2

Comments

Alternatively, this is the quadratic form with Gram matrix [ 2, 1, 1; 1, 4, 2; 1, 2, 4 ].

This is the digonal I lattice (the even holotype) of dimension 3.

Links

John Cannon, Table of n, a(n) for n = 0..5000

G. Nebe and N. J. A. Sloane, Home page for this lattice

Example

1 + 2*q^2 + 10*q^4 + 4*q^6 + 10*q^8 + 2*q^10 + 16*q^12 + 4*q^14 + 26*q^16 + ...

Crossrefs

Sequence in context: A102512 A344794 A196364 * A189881 A189872 A319407

Adjacent sequences: A029670 A029671 A029672 * A029674 A029675 A029676

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved