  A very simple procedure to calculate eigenenergies of quantum anharmonic
oscillators is presented. The method, exact but for numerical computations,
consists merely in requiring the vanishing of the Wronskian of two solutions
which are regular respectively at the origin and at infinity. The first one can
be represented by its series expansion; for the second one, an asymptotic
expansion is available. The procedure is illustrated by application to quartic
and sextic oscillators.
