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A226281
Least number k such that 3^(2^i) + k is prime for i = 0,1,..,n-1.
5
2, 2, 2, 2, 58, 440, 18248, 2024098, 4263330280, 22836544460, 40728071843930
OFFSET
1,1
COMMENTS
Generalized Fermat primes of the form b^(2^i) + k.
EXAMPLE
a(5) = 58 because k = 58 is the minimal k such that N = 3^(2^i) + k is prime for i = 0, 1, 2 ,3 ,4; N = 61, 67, 139, 6619, 43046779. But 3^(2^5) + 58 is divisible by 37 and three other primes.
CROSSREFS
Sequence in context: A154288 A225057 A084954 * A217993 A049300 A339017
KEYWORD
nonn,more
AUTHOR
Robin Garcia, Jun 02 2013
EXTENSIONS
a(11) from Giovanni Resta, Jun 17 2013
STATUS
approved