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A129615
a(n) is the smallest natural number m such that 4^4^k + m is prime for k=0,1,...,n.
4
1, 1, 15, 385, 137593, 106908087
OFFSET
0,3
COMMENTS
Next term is greater than 3*10^8.
EXAMPLE
For k=0,1,...,5 4^4^k + 106908087 are prime and 106908087 is the smallest number with this property so a(5)=106908087.
CROSSREFS
Sequence in context: A145409 A164323 A374000 * A286139 A069990 A157581
KEYWORD
hard,more,nonn
AUTHOR
Farideh Firoozbakht, May 13 2007
STATUS
approved