%I #22 Oct 13 2019 02:54:24
%S 0,2552,4892,7896,14352,32124,51476
%N Numbers k such that 74*2^k-1 is prime.
%C Equals A050544 minus one; A050544 is the main entry for this sequence. - _Jeppe Stig Nielsen_, Oct 09 2019
%D Computed by Joe K. Crump (joecr(AT)carolina.rr.com) and (mostly) by _David Broadhurst_.
%H Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a>
%H Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>
%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>
%o (PARI) is(n)=ispseudoprime(74*2^n-1) \\ _Charles R Greathouse IV_, May 22 2017
%Y Cf. A050412, A050544.
%K nonn,hard
%O 1,2
%A _David Broadhurst_, Dec 22 1999
%E _David Broadhurst_, Dec 26 1999 reports that primality up to n=51476 is now proved, using Yves Gallot's proth.exe.
|