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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Next term is greater than 3*10^8.

LINKS

Table of n, a(n) for n=0..5.

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

Cf. A129613, A129614.

Sequence in context: A324415 A145409 A164323 * A286139 A069990 A157581

Adjacent sequences:  A129612 A129613 A129614 * A129616 A129617 A129618

KEYWORD

hard,more,nonn

AUTHOR

Farideh Firoozbakht, May 13 2007

STATUS

approved

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Last modified April 17 02:26 EDT 2021. Contains 343059 sequences. (Running on oeis4.)