1,2

2^3+2^1+1=11 prime so a(1)=1

2^5+2^2+1=37 prime so a(2)=2

2^7+2^3+1=137 prime so a(3)=3

Sequence in context: A110542 A101542 A101581 this_sequence A094206 A118998 A003432

Adjacent sequences: A105177 A105178 A105179 this_sequence A105181 A105182 A105183

more,nonn

Pierre CAMI (pierrecami(AT)tele2.fr), Apr 11 2005