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 A098168 Prime index j such that prime(j) = the n-th fortunate number, A005235(n). 1
 2, 3, 4, 6, 9, 7, 8, 9, 12, 18, 19, 18, 20, 15, 28, 17, 18, 29, 24, 27, 22, 36, 45, 26, 27, 51, 48, 31, 48, 43, 38, 50, 117, 52, 37, 39, 85, 52, 46, 43, 46, 76, 51, 133, 65, 137, 111, 65, 76, 62, 86, 67, 61, 59, 58, 79, 63, 67, 75, 94, 67, 64, 78, 67, 71, 81, 82, 153, 101, 221 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MATHEMATICA NextPrime[n_Integer] := Block[{k}, k = n + 1; While[ !PrimeQ[k], k++ ]; k]; Fortunate[n_Integer] := Block[{p = Product[Prime[i], {i, 1, n}] + 1, q}, q = NextPrime[p]; q - p + 1]; Table[ PrimePi[ Fortunate[n]], {n, 70}] (* Robert G. Wilson v, Sep 04 2004 *) CROSSREFS Cf. A005235 A055211 A098166 A098167. Sequence in context: A185290 A141396 A159849 * A306441 A207831 A207826 Adjacent sequences:  A098165 A098166 A098167 * A098169 A098170 A098171 KEYWORD nonn AUTHOR Pierre CAMI, Aug 30 2004 EXTENSIONS More terms from Robert G. Wilson v, Sep 04 2004 Better definition from R. J. Mathar, Oct 28 2007 STATUS approved

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Last modified August 4 21:32 EDT 2021. Contains 346455 sequences. (Running on oeis4.)