A093941 Primes of the form 5*10^k + 7*R_k, where R_k is the repunit (A002275) of length k.

5, 577, 577777777, 577777777777777, 577777777777777777, 5777777777777777777, 5777777777777777777777777777777777, 577777777777777777777777777777777777

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Makoto Kamada, Prime numbers of the form 577...77.

Index entries for primes involving repunits.

Crossrefs

Cf. A002275, A056715 (corresponding k).

Sequence in context: A298651 A299605 A185555 * A072952 A179634 A302379

Adjacent sequences: A093938 A093939 A093940 * A093942 A093943 A093944

Keyword

nonn

Author

Rick L. Shepherd, Apr 17 2004

Status

approved