  We show how the generalized Lambert series sum(n>=1, x*q^n/(1-x*q^n)) can be
computed with Theta convergence. This allows the computation of the sum of the
inverse Fibonacci numbers without splitting the sum into even and odd part. The
method is a special case of an expression for the more general series sum(n>=0,
t^n/(1-x*q^n)), which can be obtained from either the Rogers-Fine identity or
an identity by Osler and Hassen.
