A065425 Smallest odd prime greater than n such that the decimal expansion of its base n conversion is also prime.

3, 67, 5, 13, 7, 17, 11, 37, 11, 31, 13, 29, 17, 41, 17, 37, 19, 41, 23, 53, 23, 113, 31, 53, 29, 109, 29, 61, 31, 71, 41, 89, 37, 73, 37, 83, 41, 89, 41, 109, 43, 89, 47, 101, 47, 97, 61, 101, 53, 113, 53, 109, 61, 113, 59, 137, 59, 127, 61, 131, 71, 137, 67, 139, 67, 137

Offset

2,1

Comments

For bases above ten, use multidigit numbers to represent the new number. See the example.

Links

Table of n, a(n) for n=2..67.

Example

a(15) = 41. 17d = 12, 19d = 14, 23d = 18, 29d = 114, 31d = 21 and 37d = 27, all of which are composite. But 41d = 211 which is a prime.

Mathematica

Do[ k = PrimePi[n] + 1; While[ !PrimeQ[ FromDigits[ IntegerDigits[ Prime[k], n]]], k++ ]; Print[ Prime[k]], {n, 2, 50} ]

Crossrefs

Cf. A065720 - A065727.

Sequence in context: A157576 A339599 A105443 * A096482 A139868 A110716

Adjacent sequences: A065422 A065423 A065424 * A065426 A065427 A065428

Keyword

base,nonn

Author

Robert G. Wilson v, Nov 15 2001

Extensions

More terms from David Wasserman, Aug 30 2002

Status

approved