A050413 Numbers k such that 74*2^k-1 is prime.

0, 2552, 4892, 7896, 14352, 32124, 51476

Offset: 1

Author

David Broadhurst, Dec 22 1999

Keywords

• nonn
• hard

Comments

Equals A050544 minus one; A050544 is the main entry for this sequence. - Jeppe Stig Nielsen, Oct 09 2019

References

• Computed by Joe K. Crump (joecr(AT)carolina.rr.com) and (mostly) by David Broadhurst.

Links

• Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300
• Wilfrid Keller, List of primes k.2^n - 1 for k < 300
• Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Crossrefs

Cf. A050412, A050544.

Programs

PARI

is(n)=ispseudoprime(74*2^n-1) \\ Charles R Greathouse IV, May 22 2017

Extensions

David Broadhurst, Dec 26 1999 reports that primality up to n=51476 is now proved, using Yves Gallot's proth.exe.