login
A032730
Numbers k such that k prefixed by '5' and followed by '9' is prime.
0
0, 6, 9, 11, 17, 18, 20, 27, 30, 39, 41, 44, 47, 51, 56, 63, 65, 66, 68, 74, 77, 83, 84, 86, 87, 93, 105, 110, 116, 119, 122, 123, 132, 134, 141, 143, 144, 147, 153, 159, 165, 167, 171, 174, 176, 182, 183, 185, 186, 189, 192, 194, 200, 206, 218, 224, 225
OFFSET
1,2
MATHEMATICA
Select[Range[0, 250], PrimeQ[FromDigits[Join[{5}, IntegerDigits[#], {9}]]]&] (* Harvey P. Dale, May 09 2011 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
EXTENSIONS
Offset changed by Andrew Howroyd, Aug 13 2024
STATUS
approved