  For a fixed integer N, and fixed numbers b_1,...,b_N, we consider sequences,
the nth term (a_n) of which is the sum of the squares of the terms in the
expansion of (b_1 + ... + b_N)^n. In the case all b_i=1, we give a formula for
a recurrence relation for the a_n. Otherwise we give an algorithm for finding a
recurrence relation. As an application, we give the Picard-Fuchs equations for
certain families of elliptic curves.
