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A138083 Numbers n such that (3^(2^n) + 1)/2 is prime. 2
0, 1, 2, 4, 5, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
See A171381, which is the main entry for this sequence.
LINKS
PROG
(PARI) is(n)=ispseudoprime((3^(2^n)+1)/2) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
Sequence in context: A327326 A170882 A116680 * A181524 A240568 A309681
KEYWORD
nonn,more,hard
AUTHOR
N. J. A. Sloane, Dec 09 2009
STATUS
approved

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)