A108260 Consider primes p and q such that p = 3^k + 14 and q = 3^(k+1) + 14 for some k; sequence gives values of p.

17, 23, 257, 19697

Offset

0,1

Comments

There are no additional terms up to k=2000, which generates a 955-digit nonprime candidate number for p. - Harvey P. Dale, Aug 17 2014

Links

Table of n, a(n) for n=0..3.

Example

3^1 + 14 = 17, 3^2 + 14 = 23.

Mathematica

Transpose[Select[Table[{3^k+14, 3^(k+1)+14}, {k, 10}], AllTrue[ #, PrimeQ]&]] [[1]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Aug 17 2014 *)

Prog

(PARI) g(m, n, b) = { for(x=0, n, y=m+b^x+b%2; z=m+b^(x+1)+b%2; if(isprime(y)&isprime(z), print1(y", ") ) ) }

Crossrefs

Sequence in context: A127924 A250640 A344636 * A062628 A127907 A070687

Adjacent sequences: A108257 A108258 A108259 * A108261 A108262 A108263

Keyword

nonn

Author

Cino Hilliard, Jun 29 2005

Status

approved