A110097 Numbers n such that the string 444n is prime.

1, 7, 17, 49, 53, 83, 91, 97, 109, 113, 121, 127, 131, 151, 167, 173, 179, 181, 187, 209, 253, 271, 281, 287, 289, 293, 307, 341, 343, 347, 349, 401, 403, 421, 443, 449, 461, 463, 469, 473, 487, 517, 523, 527, 529, 539, 547, 553, 557, 569, 589, 607, 623, 637

Offset

1,2

Links

Table of n, a(n) for n=1..54.

Example

If n=113 then 444n = 444113 (prime).

Mathematica

Select[Range[1000], PrimeQ[FromDigits[Join[{4, 4, 4}, IntegerDigits[#]]]]&] (* Harvey P. Dale, Dec 02 2010 *)

Crossrefs

Sequence in context: A195905 A104164 A192244 * A179262 A018672 A221591

Adjacent sequences: A110094 A110095 A110096 * A110098 A110099 A110100

Keyword

nonn,base

Author

Parthasarathy Nambi, Sep 05 2005

Extensions

More terms from Vincenzo Librandi, Mar 27 2010

Status

approved