1,2

Also numbers n such that (17*10^n+1)/9 is prime.

Makoto Kamada, Factorizations of 188...889.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(17*10^n + 1)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A089428 A063801 A160320 this_sequence A132515 A036300 A167368

Adjacent sequences: A102942 A102943 A102944 this_sequence A102946 A102947 A102948

more,nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 16 2004