OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
k=2 is in the sequence because k3333 = 23333 is prime.
k=73 is in the sequence because k3333 = 733333 is prime.
k=125 is in the sequence because k3333 = 1253333 is prime.
MATHEMATICA
Select[Range[500], PrimeQ[FromDigits[Join[IntegerDigits[#], {3, 3, 3, 3}]]]&] (* Harvey P. Dale, Jun 17 2014 *)
Select[Range[500], PrimeQ[#*10^4+3333]&] (* Harvey P. Dale, Jun 15 2024 *)
PROG
(Magma) [ n: n in [1..700] | IsPrime(Seqint([3, 3, 3, 3] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 04 2011
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Feb 20 2005
STATUS
approved