A032707 Numbers k such that k prefixed by '7' and followed by '1' is prime.

0, 5, 6, 12, 15, 21, 32, 33, 35, 41, 45, 48, 54, 56, 59, 62, 68, 69, 74, 84, 90, 95, 101, 108, 116, 117, 119, 126, 134, 141, 147, 155, 167, 171, 174, 176, 182, 186, 188, 194, 197, 203, 209, 210, 216, 221, 222, 225, 227, 234, 242, 243, 246, 248, 255, 266

Offset

1,2

Links

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

Mathematica

n71Q[n_]:=PrimeQ[FromDigits[Join[{7}, IntegerDigits[n], {1}]]]; Select[ Range[ 0, 300], n71Q] (* Harvey P. Dale, Jun 20 2017 *)

Crossrefs

Cf. A032702-A032733.

Sequence in context: A185031 A138925 A088767 * A240756 A127306 A319184

Adjacent sequences: A032704 A032705 A032706 * A032708 A032709 A032710

Keyword

nonn,base

Author

Patrick De Geest, May 15 1998

Extensions

Offset changed by Andrew Howroyd, Aug 11 2024

Status

approved