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Consider primes p with least positive primitive root g such that q=p+g is next prime after p; sequence gives values of g.
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%I #17 May 08 2018 15:11:55

%S 1,2,2,2,2,2,2,2,2,6,2,2,2,6,2,6,10,2,6,2,2,2,6,2,2,6,6,2,10,2,2,2,2,

%T 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,6,6,2,6,2,6,6,2,6,2,2,2,2,2,2,2,2,2,

%U 2,2,6,2,2,10,2,2,2,2,6,2,6,2,2,2,2,6,2,2,2,2,10,6,10,2,2,2,10,2,2,2,6,10

%N Consider primes p with least positive primitive root g such that q=p+g is next prime after p; sequence gives values of g.

%D M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 864.

%H T. D. Noe, <a href="/A047935/b047935.txt">Table of n, a(n) for n=1..1000</a>

%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

%H <a href="/index/Pri#primes_root">Index entries for primes by primitive root</a>

%e 11 has primitive root 2 and 11+2 = 13 is prime after 11, which contributes a 2 to the sequence.

%t f[p_] := {g = PrimitiveRoot[p], p + g == NextPrime[p]};

%t A047935 = Select[f /@ Prime /@ Range[1000], #[[2]]& ][[All, 1]](* _Jean-François Alcover_, Feb 15 2012 *)

%Y Cf. A047933, A047934. See also A001918.

%K nice,nonn

%O 1,2

%A _Felice Russo_

%E More terms from _James A. Sellers_, Dec 22 1999