A032704 Numbers k such that k prefixed by '4' and followed by '1' is prime.

0, 2, 3, 6, 9, 11, 20, 21, 23, 24, 26, 27, 39, 42, 44, 45, 48, 56, 59, 62, 65, 69, 72, 75, 80, 83, 86, 87, 93, 95, 101, 105, 108, 113, 114, 116, 120, 122, 123, 128, 134, 135, 138, 141, 149, 152, 161, 162, 164, 165, 168, 176, 177, 180, 185, 191, 194, 198, 206

Offset

1,2

Links

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

Mathematica

Select[Range[0, 250], PrimeQ[FromDigits[Join[{4}, IntegerDigits[#], {1}]]]&] (* Harvey P. Dale, Aug 30 2025 *)

Crossrefs

Cf. A032702-A032733.

Sequence in context: A018537 A018331 A383746 * A029805 A082007 A064417

Adjacent sequences: A032701 A032702 A032703 * A032705 A032706 A032707

Keyword

nonn,base

Author

Patrick De Geest, May 15 1998

Extensions

Offset changed by Andrew Howroyd, Aug 11 2024

Status

approved