A034599 Theta series of (putative) extremal 2-modular even lattice in dimension 20.

1, 0, 3960, 168960, 2094840, 16625664, 80652000, 343664640, 1073639160, 3299450880, 8000389584, 20081064960, 41278084320, 90307768320, 165298921920, 327406565376, 549720551160, 1009911767040, 1587054299160, 2748047385600, 4095742639824, 6764533923840

Offset

0,3

Comments

This is almost certainly the same sequence as A007038 (this would follow if the lattice R_20 is 2-modular). - N. J. A. Sloane, Sep 23 2019

Links

Table of n, a(n) for n=0..21.

H.-G. Quebbemann, Modular lattices in Euclidean spaces, J. Number Theory, 54 (1995), 190-202.

Formula

G.f.: t(x)^5 - 120*t(x)*d(x) where t(x) is the g.f. for A004011 and d(x) is the g.f. for A002288. - Sean A. Irvine, Oct 25 2025

Crossrefs

Cf. A007038. [R. J. Mathar, Oct 20 2008]

Sequence in context: A319800 A373391 A007038 * A222783 A107540 A210787

Adjacent sequences: A034596 A034597 A034598 * A034600 A034601 A034602

Keyword

nonn,changed

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Oct 25 2025

Status

approved