1,2

Also numbers n such that (53*10^n+1)/9 is prime.

Makoto Kamada, Factorizations of 588...889.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(53*10^n + 1)/9], Print[n]], {n, 0, 10000}]

Adjacent sequences: A103021 A103022 A103023 this_sequence A103025 A103026 A103027

Sequence in context: A061517 A058759 A032474 this_sequence A131041 A081843 A004938

more,nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 18 2005