1,3

Also numbers n such that (25*10^n-43)/9 is prime.

Makoto Kamada, Factorizations of 277...773.

Index entries for primes involving repunits.

Do[ If[ PrimeQ[(25*10^n - 43)/9], Print[n]], {n, 0, 10000}]

Sequence in context: A098449 A118378 A003086 this_sequence A085649 A152396 A048873

Adjacent sequences: A102955 A102956 A102957 this_sequence A102959 A102960 A102961

more,nonn

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