The wikipedia article on Gottfried Wilhelm Leibniz mentions, in the chapter on symbolic thought, that: "Leibniz saw that the uniqueness of prime factorization suggests a central role for prime numbers in the universal characteristic, a striking anticipation of Gödel numbering. Granted, there is no intuitive or mnemonic way to number any set of elementary concepts using the prime numbers".
First of all, as far as I understand, Gödel numbering is an operation that does assign a prime number to every elementary symbol (or the elementary concept it represents) or logical operation (such as logical conjuction) , and therefore the second sentence is unclear to me. Secondly, i'd like to get a reference about the manuscript\s in which Leibniz anticipated Gödel numbering (of which the wikipedia claim is based). I guess it's in of his writings on "characteristic numbers" and the "calculus of propositions", but the Leibniz's nachlass is too vast and i don't know where to find the relevant material.
Everyone with useful information is welcomed to contribute to the answer of my question.