1,2

Also numbers n such that (68*10^n-23)/9 is prime.

Makoto Kamada, Factorizations of 755...553.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(68*10^n - 23)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A081420 A039277 A045019 this_sequence A022384 A093022 A057342

Adjacent sequences: A103058 A103059 A103060 this_sequence A103062 A103063 A103064

more,nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 19 2005