A033668 - OEIS

A033668

Theta series of 4-dimensional lattice A_2 tensor A2, with det 81, minimal norm 4.

1, 0, 18, 12, 0, 36, 36, 0, 90, 12, 0, 72, 84, 0, 144, 72, 0, 108, 36, 0, 252, 96, 0, 144, 180, 0, 252, 12, 0, 180, 216, 0, 378, 144, 0, 288, 84, 0, 360, 168, 0, 252, 288, 0, 504, 72, 0, 288, 372, 0, 558, 216, 0, 324

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..53.

FORMULA

After rescaling, this is equal to (theta series of A2)^2 + 2*(theta series of A_2 with respect to deep hole)^2, i.e. J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 111, Eq. (60)^2 + 2*Eq.(63)^2.

CROSSREFS

Sequence in context: A247604 A194659 A194186 * A030239 A040308 A077810

Adjacent sequences: A033665 A033666 A033667 * A033669 A033670 A033671

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved