OFFSET
0,1
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 107.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
G. Nebe and N. J. A. Sloane, Home page for this lattice
FORMULA
a(n) = 4*A045828(n).
MATHEMATICA
terms = 52; QP = QPochhammer; s = 4*(QP[q^2]^3*QP[q^4]^2)/QP[q]^2 + O[q]^terms; CoefficientList[s, q] (* Jean-François Alcover, Jul 05 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved