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 A213007 Decimal expansion of Brun's quadruple primes constant. 2
 8, 7, 0, 5, 8, 8, 3, 8 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Infinite sum of the reciprocals of p, p+2, p+6, and p+8, where p ranges over all elements of A007530. The 9th digit is probably 0. LINKS T. R. Nicely, Enumeration to 1.6e15 of the prime quadruplets. Wikipedia, Brun's theorem. Wikipedia, Prime quadruplet. FORMULA Sum_{n >= 1} (1/c(n) + 1/(c(n)+2) + 1/(c(n)+6) + 1/(c(n)+8)), where c(n) = A007530(n). EXAMPLE 0.8705883800[+-5] CROSSREFS Cf. A007530, A194098, A194098, A065421. Sequence in context: A051762 A247017 A198112 * A155094 A294969 A292821 Adjacent sequences:  A213004 A213005 A213006 * A213008 A213009 A213010 KEYWORD nonn,cons,hard,more AUTHOR Stanislav Sykora, Jun 01 2012 STATUS approved

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Last modified September 24 00:30 EDT 2018. Contains 315306 sequences. (Running on oeis4.)