  We define an infinite sequence of superconformal indices, I_n, generalizing
the Schur index for N=2 theories. For theories of class S we then suggest a
recursive technique to completely determine I_n. The information encoded in the
sequence of indices is equivalent to the N=2 superconformal index depending on
the maximal set of fugacities. Mathematically, the procedure suggested in this
note provides a perturbative algorithm for computing a set of eigenfunctions of
the elliptic Ruijsenaars-Schneider model.
