A179687 - OEIS

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A179687

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

3, 5, 7, 19, 27, 37, 47, 53, 67, 95, 101, 103, 107, 131, 149, 173, 181, 191, 227, 239, 263, 293, 311, 317, 349, 359, 367, 373, 383, 419, 461, 463, 479, 509, 547, 557, 587, 613, 619, 647, 653, 677, 701, 743, 751, 773, 787, 821, 841, 863, 887, 947

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OFFSET

1,1

COMMENTS

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

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).

LINKS

Table of n, a(n) for n=1..52.

CROSSREFS

Cf. A179382, A179383, A179480, A179481, A179686

Sequence in context: A154524 A184805 A079131 * A106919 A005850 A052334

Adjacent sequences: A179684 A179685 A179686 * A179688 A179689 A179690

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Jul 24 2010

EXTENSIONS

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

STATUS

approved