A249509 Smallest number k >= A000043(n) such that k*A000668(n)*(k*A000668(n)+1)-1 is prime.

2, 3, 5, 7, 25, 19, 20, 42, 96, 190, 134, 164, 650, 852, 1455, 2765, 2480, 3960, 5464, 6694, 17206, 13118, 13680, 28481, 27445, 28821, 101696, 116232, 142083, 187376, 250118, 1200007

Offset: 1

Author

Pierre CAMI, Oct 30 2014

Keywords

• nonn

Comments

a(34) = 1200007.

A000043(34) = 756839.

A000668(34) = 2^756839-1.

1200007*(2^756839-1)*(1200007*(2^756839-1)+1)-1 is a 455675 digits certified prime using PFGW.

Links

• Chris K. Caldwell, The List of Largest Known Primes, Prime corresponding to a(34)

Crossrefs

Cf. A000043, A000668, A137908, A137909.