### Abstract

The strong parallel between conjectural asymptotics of the 2n-th moment of zeta (Conrey, Farmer, Keating, Rubinstein and Snaith) with a ``constant term'' of an Eisenstein series on GL(2n) will be reviewed. For the second moment, the parallel is explained by the Voronoi-Oppenheim summation formula. For larger n, divisor functions of lattices will be defined and a pleasant new Voronoi-type summation formula will be proved for the lattice divisor functions, making use of Bessel functions associated with the Shalika-Kirillov model of a degenerate principal series representation of GL(2n,R).