1,3

Also numbers n such that (29*10^n-11)/9 is prime.

Makoto Kamada, Factorizations of 322...221.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(29*10^n-11)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A139416 A013563 A009788 this_sequence A053569 A115283 A078382

Adjacent sequences: A102963 A102964 A102965 this_sequence A102967 A102968 A102969

more,nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 17 2004