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A029671 Theta series of quadratic form with Gram matrix [ 2, 1, 0; 1, 4, 1; 0, 1, 4 ]. 1
1, 2, 6, 8, 6, 8, 4, 8, 18, 10, 4, 20, 16, 0, 12, 16, 14, 16, 18, 12, 24, 8, 12, 32, 12, 14, 2, 32, 20, 16, 16, 8, 42, 16, 8, 40, 30, 16, 28, 0, 12, 12, 24, 32, 40, 24, 8, 40, 32, 14, 30, 32, 0, 40, 16, 16, 36, 24, 20, 44, 40, 8, 28, 40, 30, 4, 16, 44, 48, 16, 16, 40, 54, 12, 28, 40, 24 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

This is the monoclinic P 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

FORMULA

a(n) = coefficient of q^2n in theta3(q)*theta3(q^3)*theta3(q^5). Theta series of even sublattice of Z+Z^3+Z^5 - Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), May 07 2002

EXAMPLE

1 + 2*q^2 + 6*q^4 + 8*q^6 + 6*q^8 + 8*q^10 + 4*q^12 + 8*q^14 + 18*q^16 + 10*q^18 + ...

CROSSREFS

Sequence in context: A145500 A065129 A074758 * A154970 A011224 A021376

Adjacent sequences:  A029668 A029669 A029670 * A029672 A029673 A029674

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 13:56 EST 2012. Contains 205921 sequences.