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A110584
Numbers n such that the string 999n is prime.
1
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
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
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Sep 12 2005
EXTENSIONS
More terms from Vincenzo Librandi, Mar 27 2010
STATUS
approved