A093631 Primes of the form 6*10^k + R_k, where R_k is the repunit (A002275) of length k.

61, 611111, 61111111, 61111111111111111111111111, 61111111111111111111111111111111, 61111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

Offset

1,1

Comments

The next term has 200 digits. - Harvey P. Dale, Dec 06 2019

Links

Table of n, a(n) for n=1..6.

Makoto Kamada, Prime numbers of the form 611...11.

Index entries for primes involving repunits

Mathematica

Select[Table[FromDigits[PadRight[{6}, n, 1]], {n, 150}], PrimeQ] (* Harvey P. Dale, Dec 06 2019 *)

Crossrefs

Cf. A002275, A056717 (corresponding k).

Sequence in context: A058996 A116124 A068533 * A087513 A176272 A173418

Adjacent sequences: A093628 A093629 A093630 * A093632 A093633 A093634

Keyword

nonn

Author

Rick L. Shepherd, Apr 06 2004

Status

approved