A110584 Numbers n such that the string 999n is prime.

23, 29, 61, 71, 89, 91, 101, 133, 149, 169, 181, 199, 217, 221, 233, 239, 269, 287, 307, 329, 331, 359, 371, 377, 389, 431, 433, 437, 451, 491, 499, 521, 529, 541, 553, 563, 599, 611, 613, 623, 631, 653, 667, 671, 683, 721, 727, 749, 763, 769, 773, 809, 853

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

If n=169 then 999n = 999169 (prime).

Mathematica

Select[Range[900], PrimeQ[999*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Sep 05 2017 *)

Crossrefs

Sequence in context: A157677 A092518 A355983 * A115396 A180538 A227217

Adjacent sequences: A110581 A110582 A110583 * A110585 A110586 A110587

Keyword

nonn,base

Author

Parthasarathy Nambi, Sep 12 2005

Extensions

More terms from Vincenzo Librandi, Mar 27 2010

Status

approved