1,2

Makoto Kamada, Factorizations of 600...007.

Sabin Tabiraca and Kieran Reynolds, Lacunary Prime Numbers.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[6*10^n + 7], Print[n]], {n, 0, 10000}]

Sequence in context: A051209 A093765 A104577 this_sequence A098506 A163168 A085453

Adjacent sequences: A103023 A103024 A103025 this_sequence A103027 A103028 A103029

more,nonn

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