Dear Seqfans, Just an ignorance-betraying question. Given positive integers n and p, p<=n, the number of lattice points t, satisfying t >= 0 and pt <= n, is, obviously, 1 + floor(n/p). Given positive integers n, p, q, p,q <= n, do we have a statement about the number of lattice points (t,s) satisfying t >= 0, s >= 0, and pt + qs <= n ? Thanks for any input. Emeric