1,2

Also numbers n such that (65*10^n+7)/9 is prime.

Makoto Kamada, Factorizations of 722...223.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(65*10^n + 7)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A051434 A074138 A120252 this_sequence A087760 A032498 A144613

Adjacent sequences: A103050 A103051 A103052 this_sequence A103054 A103055 A103056

more,nonn

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