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 A122989 Decimal expansion of Sum_{n >= 1} 1/A007504(n), where A007504(n) is the sum of the first n primes. 1
 1, 0, 2, 3, 4, 7, 6, 3, 2, 3, 9, 2, 0, 1, 2 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Summing k=4016708412 primes, I get prime(k)=97434417233, primeSum=191462469311735988657, seriesSum=1.02347632390000000000618+. And I compute an upper bound of 1.02347632395-. - Don Reble, May 14 2007 Summed through k = 2562700000000 primes.  Upper bound = 1.0234763239201294.  Lower bound = 1.0234763239201286. - Robert Price, May 05 2013 LINKS EXAMPLE 1/2 + 1/5 + 1/10 + 1/17 + 1/28 + 1/41 + 1/58 + 1/77 + 1/100 + ... = 1.023476329... CROSSREFS Cf. A007504. Sequence in context: A167151 A273014 A072275 * A222246 A321726 A267299 Adjacent sequences:  A122986 A122987 A122988 * A122990 A122991 A122992 KEYWORD cons,nonn,more AUTHOR Pierre CAMI, Oct 28 2006 EXTENSIONS A number of contributors worked on the difficult question of computing this constant accurately. The above comment from Don Reble gives the tightest bounds presently known. It had been suggested that the true value might be Pi/6 + 1/2 = 1.0235987755982988730771..., but that is now disproved. - N. J. A. Sloane, Jun 15 2007 Corrected a(10), added a(11)-a(15) from Robert Price, May 05 2013 STATUS approved

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Last modified December 15 20:00 EST 2019. Contains 330000 sequences. (Running on oeis4.)