OFFSET
1,1
COMMENTS
All terms are even since for odd k, 2^k - 11 is divisible by 3.
LINKS
Henri Lifchitz and Renaud Lifchitz, Search for 2^n-11, PRP Top Records.
EXAMPLE
k = 6: 64 - 11 = 53 is prime.
MATHEMATICA
Select[Range[4, 20000], PrimeQ[2^#-11]&] (* Vladimir Joseph Stephan Orlovsky, Feb 26 2011*)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Labos Elemer, Jul 13 2004
EXTENSIONS
a(13)-a(16) from Max Alekseyev, a(17)-a(18) from Henri Lifchitz, added by Max Alekseyev, Feb 09 2012
a(19) from Lelio R Paula, added by Max Alekseyev, Oct 24 2013
a(20)-a(22) from Stefano Morozzi, added by Elmo R. Oliveira, Nov 16 2023
STATUS
approved