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a(n) = 2*q(n)-1 where q(n) is the sequence of records positions of A179686
2

%I #5 Mar 30 2012 18:52:59

%S 3,5,7,19,27,37,47,53,67,95,101,103,107,131,149,173,181,191,227,239,

%T 263,293,311,317,349,359,367,373,383,419,461,463,479,509,547,557,587,

%U 613,619,647,653,677,701,743,751,773,787,821,841,863,887,947

%N a(n) = 2*q(n)-1 where q(n) is the sequence of records positions of A179686

%C The record positions are q(n) = 2, 3, 4, 10, 14, 19, 24, 27, 34,...

%C Sequences A179382, A179383, A179480, A179481, A179686 and this sequence show that their terms depend on prime power factorization of 2*n-1. Nevertheless, this question yet is waiting its research. Most likely that almost all terms of this sequence are primes (27, 95, 841,... are not).

%Y Cf. A179382, A179383, A179480, A179481, A179686

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Jul 24 2010

%E Extended beyond a(7) by R. J. Mathar, Dec 04 2011