A032729 Numbers k such that k prefixed by '4' and followed by '9' is prime.

0, 1, 3, 4, 7, 9, 12, 13, 15, 21, 22, 25, 28, 33, 34, 40, 51, 54, 63, 64, 67, 72, 75, 78, 79, 88, 90, 91, 96, 99, 103, 114, 117, 118, 126, 129, 138, 139, 147, 151, 153, 154, 157, 160, 165, 166, 171, 172, 175, 180, 184, 187, 195, 196, 199, 201, 208, 213, 216

Offset: 1

Author

Patrick De Geest, May 15 1998

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A032702-A032733.

Programs

Mathematica

Select[Range[0,300],PrimeQ[FromDigits[Join[{4},IntegerDigits[#],{9}]]]&] (* Harvey P. Dale, Jun 04 2019 *)