OFFSET

1,1

COMMENTS

Though initial terms match it is different from A039726, in that a smaller prime may appear later.

Some of the larger entries may only correspond to probable primes.

A158076 suggests that the numbers in this sequence can be generated quite easily/quickly. Perhaps this sequence is a fast method to generate large probable primes. [Dmitry Kamenetsky, Mar 12 2009]

Records: 2, 3, 5, 7, 11, 19, 29, 59, 67, 97, 113, 233, 251, 587, 881, 953, 1231, 1327, 1553, 1657, 2383, 3251, 3769, 6737, 6947, 7103, 7879, 8263, 10159, 11369, 22003, ..., . - Robert G. Wilson v, Jul 20 2017

Position of the n_th prime: 1, 2, 3, 4, 5, 8, 472, 6, 57, 7, 11, 10, 15, 20, 12, 14, 9, 23, 13, 21, 17, 30, 55, 478, 16, 26, 19, 28, 25, 18, 50, 345, 35, 36, 45, 24, ..., . - Robert G. Wilson v, Jul 20 2017

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..700 (first 100 terms from Amarnath Murthy and Meenakshi Srikanth)

EXAMPLE

The n-th term is the smallest prime that is not already in the sequence, such that one plus the product of the first n terms is prime. [Dmitry Kamenetsky, Mar 12 2009]

MATHEMATICA

f[s_List] := Block[{p = Times @@ s, q = 2}, While[ MemberQ[s, q] || !PrimeQ[p*q + 1], q = NextPrime@ q]; Append[s, q]]; Nest[f, {2}, 63] (* Robert G. Wilson v, Jul 20 2017 *)

PROG

CROSSREFS

KEYWORD

nonn

AUTHOR

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 06 2003

EXTENSIONS

More terms from Rick L. Shepherd, Mar 18 2004

STATUS

approved