A077007 Primes p such that p*q+1 or p*q-1 is divisible by r where q = nextprime(p) and r=nextprime(q).

2, 3, 7, 17, 31, 1321

Offset

1,1

Comments

a(7) > 10^8.

Links

Table of n, a(n) for n=1..6.

Example

7 is a member as 13 divides 7*11 + 1 = 78. 17 is a member as 23 divides 17*19 -1 = 322.

Crossrefs

Sequence in context: A349665 A030086 A078721 * A158498 A391962 A267601

Adjacent sequences: A077004 A077005 A077006 * A077008 A077009 A077010

Keyword

nonn

Author

Amarnath Murthy, Oct 26 2002

Extensions

One more term from Ralf Stephan, Oct 31 2002

Offset changed by Sean A. Irvine, Apr 25 2025

Status

approved