%I A098168
%S A098168 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,
%T A098168 48,31,48,43,38,50,117,52,37,39,85,52,46,43,46,76,51,133,65,137,111,65,
%U A098168 76,62,86,67,61,59,58,79,63,67,75,94,67,64,78,67,71,81,82,153,101,221
%N A098168 Prime index j such that prime(j) = the n-th fortunate number, A005235(n).
%t A098168 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}] (from Robert G. Wilson v Sep 04 2004)
%Y A098168 Cf. A005235 A055211 A098166 A098167.
%Y A098168 Sequence in context: A113199 A141396 A159849 this_sequence A035312 A056230 
               A119919
%Y A098168 Adjacent sequences: A098165 A098166 A098167 this_sequence A098169 A098170 
               A098171
%K A098168 nonn
%O A098168 1,1
%A A098168 Pierre CAMI (pierrecami(AT)tele2.fr), Aug 30 2004
%E A098168 More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 04 2004
%E A098168 Better definition from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 
               28 2007