1,2

Also numbers n such that (49*10^n-13)/9 is prime.

Makoto Kamada, Factorizations of 544...443.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(49*10^n - 13)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A034418 A034421 A029448 this_sequence A116552 A124285 A131326

Adjacent sequences: A103011 A103012 A103013 this_sequence A103015 A103016 A103017

more,nonn

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