OFFSET
1,1
COMMENTS
This is a special case of prime chains generated by f(x) = cx + d.
Is it smallest initial prime of a prime chain of length n under the iteration x->2x+3, or not? At least up to 3388516667 it is the smallest one. - Zak Seidov, Dec 20 2013
LINKS
D. H. Lehmer, On certain chains of primes, Proc. London Math. Soc. (3) 14a 1965 183-186.
EXAMPLE
a(3) = 2 since 2, 2*2+3=7 and 2*7+3=17 are primes.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
W. Edwin Clark, Jun 14 2003
EXTENSIONS
More terms from Don Reble, Nov 07 2007
STATUS
approved