Various observations about infinite series
This is the paper in which Euler product expansions first appeared. Among other things, he uses it to show that the reciprocal prime sum is asymptotic to log(log(x)) as x approaches ∞.
Original Source Citation
Commentarii academiae scientiarum Petropolitanae, Volume 9, pp. 160-188.
Opera Omnia Citation
Series 1, Volume 14, pp.217-244.