1,1

The sequence of repunit primes is a subsequence of this sequence.

prime(15)=47 and (10^47-1)/9=35121409*316362908763458525001406154038726382279

so a(15)=35121409.

Cf. A004022.

Sequence in context: A107598 A087100 A102380 this_sequence A157883 A038317 A157781

Adjacent sequences: A147552 A147553 A147554 this_sequence A147556 A147557 A147558

nonn

Farideh Firoozbakht (mymontain(AT)yahoo.com), Dec 26 2008