

A050413


Numbers k such that 74*2^k1 is prime.


2




OFFSET

1,2


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

Table of n, a(n) for n=1..7.
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^n1 (or k*2^n+1) is prime


PROG

(PARI) is(n)=ispseudoprime(74*2^n1) \\ Charles R Greathouse IV, May 22 2017


CROSSREFS

Cf. A050412, A050544.
Sequence in context: A327771 A035876 A072435 * A050544 A185516 A235085
Adjacent sequences: A050410 A050411 A050412 * A050414 A050415 A050416


KEYWORD

nonn,hard


AUTHOR

David Broadhurst, Dec 22 1999


EXTENSIONS

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


STATUS

approved



