One of the Hadamard- La Vallee-Poussin constant 1.034653881897438 = gamma + Sum((log(1-1/p)+ 1/(p-1)) with p prime. References Hardy and Wright, An Introduction to the Theory of Numbers, Oxford 1960, chap 22.11 P. Erdos and M. Kac , American journal of Math. 26, 1940 738-742. also Knuth, D.E., The Art of Computer Programming, vol. 2, Seminumerical Algorithms, page 368 (section 4.5.4)