The ratio $L(A,1)/\Omega_A$

Extending classical work on elliptic curves, A. Agashé and I found a computable formula for the rational number $L(A,1)/\Omega_A$under reasonably general hypothesis. Using similar techniques, I hope to find computable formulas for rational parts of special values of twists, and of L-functions attached to forms of weight greater than two. I have already computed $L(A,1)/\Omega_A$ for several thousand abelian varieties, and hope to extend these computations.