  Finite-dimensional nonrelativistic conformal Lie algebras spanned by
polynomial vector fields of Galilei spacetime arise if the dynamical exponent
is z=2/N with N=1,2,.... Their underlying group structure and matrix
representation are constructed (up to a covering) by means of the Veronese map
of degree N. Suitable quotients of the conformal Galilei groups provide us with
Newton-Hooke nonrelativistic spacetimes with a quantized reduced negative
cosmological constant \lambda=-N.
