A032717 Numbers k such that k prefixed by '9' and followed by '3' is prime.

5, 8, 10, 13, 17, 20, 28, 29, 32, 34, 40, 41, 43, 46, 47, 53, 61, 62, 64, 73, 74, 80, 83, 88, 92, 97, 103, 115, 116, 118, 119, 124, 125, 128, 130, 137, 139, 142, 143, 145, 146, 149, 151, 157, 158, 167, 170, 173, 175, 181, 182, 187, 194, 200, 203, 208, 214

Offset: 1

Author

Patrick De Geest, May 15 1998

Keywords

• nonn
• base

Examples

			953 is prime, so 5 is a term.
		

Links

• Matthew House, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A032702-A032733.

Programs

Mathematica

Select[Range[250],PrimeQ[FromDigits[Join[{9},IntegerDigits[#],{3}]]]&] (* Harvey P. Dale, Jul 30 2013 *)

Extensions

Offset corrected by Matthew House, Jan 15 2017