%I #2 Mar 30 2012 17:26:22
%S 8,10,17,22,24,35,41,46,52,57,72,87,92,95,109,128,140,204,207,228,239,
%T 256,303,357,393,417,430,558,646,669,685,712,950,1117,1198,1315,1389,
%U 1454,1526,1543,1600,1794,2140,2289,2312,2425,2571,2851,3368,3613,3824
%N Numbers m such that greatest prime divisor of (m-th prime + 1) is 5.
%C Or, position of 5 in A023509 Greatest prime divisor of n-th prime + 1.
%F A023509(m)=5.
%t Reap[Do[If[FactorInteger[Prime[n]+1][[ -1,1]]==5,Sow[n]],{n,5000}]][[2,1]]
%Y Cf. A023509.
%K nonn
%O 1,1
%A _Zak Seidov_, Sep 09 2006