1,1

a(n)=2 whenever A165767(n) is even.

a(n)=(2^A165767(n)-A165767(n))/A165769(n).

17377902756647509 is in this sequence because it is the smallest prime factor of the semiprime 2^199-199.

Sequence in context: A158616 A127821 A114724 this_sequence A009258 A009204 A023642

Adjacent sequences: A165765 A165766 A165767 this_sequence A165769 A165770 A165771

nonn

M. F. Hasler (MHasler(AT)univ-ag.fr), Oct 08 2009