I. The formula referred to in the title is (I) below. The usefulness of the formula is based on the fact that it relates the value of a meromorphic function f(z) at a point of a sector to integrals of log If(z) I over arcs in this sector. Since such integrals are very directly related to the quantities considered in the Nevanlinna theory, the formula is easier to use than the usual Green's function formula for functions meromorphie in a sector which involves integrals of log Ifl along the boundary of the sector. An essentially equivalent formula was used by V. P. Petrenko in his proof of Paley's Conjecture [3]. By casting out some terms that were negligible for his purpose Petrenko actually complicated his proof, the complete formula (I) can be proved quite simply. Petrenko's Formula. Let f(z) b emeromorphic i_~n