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A129614
a(n) is the smallest natural number m such that 3^(3^k) + m is prime for k=0,1,...,n.
4
2, 2, 4, 16, 346, 390410, 390410, 34712918410, 40501164004
OFFSET
0,1
COMMENTS
Next term is greater than 2*10^8.
EXAMPLE
For k=0,1,...,6 3^3^k + 390410 are prime and 390410 is the smallest number with this property so a(6)=390410.
CROSSREFS
Sequence in context: A168089 A165420 A171163 * A070283 A070282 A267218
KEYWORD
hard,more,nonn
AUTHOR
Farideh Firoozbakht, May 13 2007, Jun 01 2007
STATUS
approved