OFFSET
0,1
COMMENTS
k must be even because 3^n is odd. - Harry J. Smith, Sep 10 2009
LINKS
Harry J. Smith, Table of n, a(n) for n = 0..225
MATHEMATICA
Do[ k = 1; While[ ! PrimeQ[ k*3^n + 1 ] || ! PrimeQ[ k*3^n - 1 ], k++ ]; Print[ k ], {n, 0, 50} ]
PROG
(PARI) { for (n=0, 225, k=0; p=3^n; until (isprime(k*p - 1) && isprime(k*p + 1), k+=2); write("b064213.txt", n, " ", k); ) } \\ Harry J. Smith, Sep 10 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 21 2001
EXTENSIONS
Offset changed from 1 to 0 by Harry J. Smith, Sep 10 2009
STATUS
approved