OFFSET
1,1
COMMENTS
Primes of the form 2*A005329(k)+1.
LINKS
Robert Israel, Table of n, a(n) for n = 1..12
EXAMPLE
For n=4, 2*(2^1 - 1)*(2^2 - 1)*(2^3 -1)*(2^4 - 1) + 1 = 2*1*3*7*15 + 1 = 631
MAPLE
R:= NULL: count:= 0: v:= 1:
for k from 1 while count < 10 do
v:= v*(2^k-1);
p:= 1+2*v;
if isprime(p) then R:= R, p; count:= count+1 fi
od:
R; # Robert Israel, May 04 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot, Feb 17 2009
EXTENSIONS
Definition and terms corrected by R. J. Mathar, Jul 10 2011
STATUS
approved