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

1,4

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).

Sequence in context: A314371 A217678 A227452 * A197257 A217175 A338558

Adjacent sequences: A138303 A138304 A138305 * A138307 A138308 A138309

Keyword

nonn

Author

T. D. Noe, Mar 14 2008

Status

approved