1,3

Also numbers n such that (5*10^n-23)/9 is prime.

Index entries for primes involving repunits

Do[ If[ PrimeQ[ 5(10^n - 1)/9 - 2], Print[n]], {n, 0, 5000}]

Sequence in context: A150673 A102942 A100504 this_sequence A101696 A136594 A097040

Adjacent sequences: A099413 A099414 A099415 this_sequence A099417 A099418 A099419

nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 14 2004