A032728 Numbers k such that k prefixed by '3' and followed by '9' is prime.

4, 5, 7, 8, 10, 11, 16, 20, 22, 25, 29, 31, 32, 35, 38, 44, 46, 49, 52, 53, 55, 65, 70, 71, 73, 76, 77, 88, 91, 92, 98, 101, 103, 106, 107, 113, 115, 118, 121, 124, 125, 131, 137, 146, 148, 164, 169, 172, 176, 179, 184, 185, 200, 202, 205, 206, 208, 209, 211

Offset

1,1

Links

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

Mathematica

Select[Range[250], PrimeQ[FromDigits[Join[{3}, IntegerDigits[#], {9}]]]&] (* Harvey P. Dale, Aug 17 2021 *)

Crossrefs

Cf. A032702-A032733.

Sequence in context: A288753 A202186 A247467 * A078577 A225387 A037259

Adjacent sequences: A032725 A032726 A032727 * A032729 A032730 A032731

Keyword

nonn,base

Author

Patrick De Geest, May 15 1998

Extensions

Offset changed by Andrew Howroyd, Aug 13 2024

Status

approved