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

Author

Parthasarathy Nambi, Feb 20 2005

Keywords

• nonn
• base

Examples

			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.
		

Links

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

Crossrefs

Cf. A101472.

Programs

Magma

[ n: n in [1..700] | IsPrime(Seqint([3,3,3,3] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 04 2011

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 *)