OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
1 is in the sequence because 3331 is prime.
59 is in the sequence because 33359 is prime.
107 is in the sequence because 333107 is prime.
MATHEMATICA
Select[Range[1000], PrimeQ[FromDigits[Join[{3, 3, 3}, IntegerDigits[ # ]]]] &] (Delarte)
Select[Range[1000], PrimeQ[333*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Jun 03 2023 *)
PROG
(Magma) [ n: n in [1..600] | IsPrime(Seqint(Intseq(n) cat [3, 3, 3])) ]; // Klaus Brockhaus, Feb 03 2011
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Sep 04 2005
EXTENSIONS
More terms from Alonso del Arte, Sep 06 2005
STATUS
approved