1,1

Also numbers n such that (83*10^n+7)/9 is prime.

Makoto Kamada, Factorizations of 922...223.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(83*10^n + 7)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A147153 A115706 A031394 this_sequence A108928 A097812 A100559

Adjacent sequences: A103091 A103092 A103093 this_sequence A103095 A103096 A103097

more,nonn

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