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A182425 a(n) the largest integer K such that (prime(n+1)-1)^(2^k)+1 for 0<=k<=K is prime. 0
4, 3, 2, 1, 0, 2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 2, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This sequence is a generalized reference to Fermat primes.
LINKS
MATHEMATICA
Table[k = 0; While[PrimeQ[(Prime[n+1] - 1)^(2^k) + 1], k++]; k - 1, {n, 100}] (* T. D. Noe, Apr 28 2012 *)
CROSSREFS
Cf. A182199.
Sequence in context: A023446 A258447 A066440 * A071692 A307335 A030586
KEYWORD
nonn
AUTHOR
Thomas Ordowski, Apr 28 2012
STATUS
approved

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Last modified February 26 02:01 EST 2024. Contains 370335 sequences. (Running on oeis4.)