A136351 - OEIS

A136351

Primorial numbers p# such that p# + 1 is a prime.

2, 6, 30, 210, 2310, 200560490130

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

This sequence is different from A121069 and A002110.

a(7)=A002110(75) has 154 digits and is too long to be listed. - R. J. Mathar, Jul 23 2008

LINKS

FORMULA

a(n) = A002110(A014545(n+1)). - Michel Marcus, Apr 05 2021

EXAMPLE

a(5)=2310 is followed by prime 2311 whereas 30030 is not followed by a prime.

PROG

(PARI)

S=[]; for(n=1, 200, k=vecprod(primes(n)); if(isprime(k+1), S=concat(S, k))); print(S) \\ Miles Englezou, Oct 28 2024

CROSSREFS

KEYWORD

easy,nonn

AUTHOR

Enoch Haga, Dec 25 2007

EXTENSIONS

Changed a(1) from 4 to 2 and edited by R. J. Mathar, Jul 23 2008

STATUS

approved