A093632 - OEIS

A093632

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

7, 71, 71111111, 71111111111111111111111111111111111111111111111111111111

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OFFSET

1,1

COMMENTS

No further terms up to 2000 digits. - Harvey P. Dale, Mar 06 2012

LINKS

MATHEMATICA

Select[Table[FromDigits[PadRight[{7}, n, 1]], {n, 2000}], PrimeQ] (* Harvey P. Dale, Mar 06 2012 *)

CROSSREFS

Cf. A002275, A056719 (corresponding k).

KEYWORD

nonn

AUTHOR

STATUS

approved