OFFSET
0,1
COMMENTS
See A126717 for the least k such that k*2^n-1 is prime.
For every n >= 1 there are infinitely many prime numbers p such that p + 1 is divisible by 2^n and not by 2^(n + 1). - Marius A. Burtea, Mar 10 2020
REFERENCES
Laurențiu Panaitopol, Alexandru Gica, Arithmetic problems and number theory, Ed. Gil, Zalău, (2006), ch. 13, p. 78, pr. 5 (in Romanian).
LINKS
Donovan Johnson, Table of n, a(n) for n = 0..1000
MATHEMATICA
Table[k = 1; While[p = k*2^n - 1; ! PrimeQ[p], k = k + 2]; p, {n, 0, 40}]
PROG
(Magma) a:=[]; for n in [0..31] do k:=1; while not IsPrime(k*2^n-1) do k:=k+2; end while; Append(~a, k*2^n-1); end for; a; // Marius A. Burtea, Mar 10 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Dec 27 2011
STATUS
approved