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 A084295 n is such that pi(n*prime(n))/n is an integer. 2
 1, 3, 47, 88, 200, 547, 12182, 15335, 39104, 58122, 73282, 150740 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(9) > 30000. - Michel Marcus, Sep 02 2019 a(13) > 200000. - Giovanni Resta, Sep 02 2019 LINKS MATHEMATICA Do[s=PrimePi[n*Prime[n]]/n; If[IntegerQ[s], Print[n]], {n, 1, 100000}] Select[Range[16000], IntegerQ[PrimePi[#*Prime[#]]/#]&] (* Harvey P. Dale, Jul 23 2015 *) PROG (PARI) isok(n) = denominator(primepi(n*prime(n))/n) == 1; \\ Michel Marcus, Sep 02 2019 CROSSREFS Cf. A000040, A000720, A033286, A057855, A084297, A084298. Sequence in context: A227171 A055058 A139845 * A141850 A003551 A054643 Adjacent sequences:  A084292 A084293 A084294 * A084296 A084297 A084298 KEYWORD nonn,hard,more AUTHOR Labos Elemer, May 27 2003 EXTENSIONS Corrected by Harvey P. Dale, Jul 23 2015 a(9)-a(12) from Giovanni Resta, Sep 02 2019 STATUS approved

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Last modified October 23 03:21 EDT 2019. Contains 328335 sequences. (Running on oeis4.)