A102340 Numbers k such that k3333 is prime.

2, 10, 14, 31, 32, 34, 35, 49, 52, 73, 74, 79, 80, 92, 95, 97, 113, 116, 118, 125, 127, 128, 134, 136, 139, 142, 148, 149, 155, 160, 169, 172, 178, 185, 196, 205, 211, 217, 224, 227, 238, 245, 251, 260, 262, 263, 265, 272, 281, 283, 284, 287, 296, 298, 304, 305, 311, 322, 323, 325, 326, 335, 343

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

Cf. A101472.

Sequence in context: A217191 A190043 A217681 * A358749 A293931 A047043

Adjacent sequences: A102337 A102338 A102339 * A102341 A102342 A102343

Keyword

nonn,base

Author

Parthasarathy Nambi, Feb 20 2005

Status

approved