OFFSET
1,2
EXAMPLE
a(7) = 751 because a(6)=47 and in 2*47-1, 2*47+1, 4*47-1, 4*47+1, ... 16*47-1, ...: 751 is the first prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
Don Reble, Jun 21 2003
STATUS
approved