The factorization method, initiated by Schrödinger [4] and modified and developed by Infeld [2], Duff [1], and Infeld and Hull [3], furnishes an elegant method of solving eigenvalue problems associated with certain ordinary differential equations of the second order. Not only the eigenvalues and eigenfunctions can thus be obtained, but also certain matrix elements associated with the eigenfunctions. Even if the method cannot be applied directly to eigenvalue problems, the factorization of an equation may still be of interest, since recurrence formulae may thus be established, e.g. for Bessel functions [3]. The connection of the method with Truesdell's [5] method of the “F -equation” has been discussed by Duff [1].