A032727 Numbers k such that k prefixed by '2' and followed by '9' is prime.

2, 3, 6, 12, 17, 23, 26, 30, 33, 38, 39, 45, 53, 54, 57, 60, 65, 68, 69, 71, 72, 74, 78, 81, 87, 90, 93, 96, 99, 101, 105, 108, 113, 114, 116, 117, 126, 131, 137, 141, 149, 152, 155, 156, 158, 159, 164, 173, 179, 183, 185, 192, 203, 207, 210, 212, 215, 218, 222

Offset

1,1

Links

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

Mathematica

Select[Range[300], PrimeQ[FromDigits[Join[{2}, IntegerDigits[#], {9}]]]&] (* Harvey P. Dale, Apr 02 2017 *)

Crossrefs

Cf. A032702-A032733.

Sequence in context: A200175 A286906 A125867 * A323392 A174801 A324177

Adjacent sequences: A032724 A032725 A032726 * A032728 A032729 A032730

Keyword

nonn,base

Author

Patrick De Geest, May 15 1998

Status

approved