> Sum n/prime(n)^2 and we have 3 places I see in 'history' for http://oeis.org/A097906 Pierre has now exampled: "For the first 100000000 primes the sum = 1,1012478922." This is reasonably close to my just-calculated 1.1012478923014213. I'll let my program run (barring someone else beating me to it) at 10^8 intervals (to 10^9) to see how the sum evolves.