A138306 Least prime p such that 2n = p + g, where g is a prime primitive root of p, or 0 if there is no such prime p.

0, 0, 0, 5, 7, 7, 0, 0, 11, 13, 17, 13, 0, 17, 23, 19, 23, 0, 0, 23, 23, 31, 43, 29, 37, 41, 37, 37, 41, 41, 43, 0, 47, 61, 41, 43, 67, 47, 47, 67, 59, 53, 73, 47, 47, 61, 53, 59, 67, 0, 59, 61, 59, 67, 97, 89, 97, 79, 71, 61, 79, 71, 73, 67, 71, 71, 97, 83, 71, 137, 113, 0, 103, 89

Offset: 1

Author

T. D. Noe, Mar 14 2008

Keywords

• nonn

Comments

Goldbach meets prime primitive prime roots. Sequence A138118 gives the number of representations for each 2n and sequence A138307 lists the values of 2n that are not represented.

Links

• T. D. Noe, Table of n, a(n) for n=1..1000

Crossrefs

Cf. A138305 (prime primitive roots).