

A159611


Indices, in the sequence of primes, of the known Fermat primes.


6




OFFSET

1,1


COMMENTS

A098006(a(n)) = 0.  Reinhard Zumkeller, Mar 26 2013


LINKS

Table of n, a(n) for n=1..5.


EXAMPLE

3, the Fermat prime corresponding to n = 0, is the 2nd prime, so a(0) = 2.
17, the Fermat prime corresponding to n = 2, is the 7th prime, so a(2) = 7.


PROG

(Haskell)
import Data.List (elemIndices)
a159611 n = a159611_list !! (n1)
a159611_list = map (+ 2) $ elemIndices 0 a098006_list
 Reinhard Zumkeller, Mar 26 2013
(PARI) for(i=0, 10, isprime(f=2^2^i+1) & print1(primepi(f), ", ")) \\ Michel Marcus, Apr 28 2016


CROSSREFS

Cf. A019434 (the Fermat primes), A000040 (the primes).
Sequence in context: A270402 A253574 A238399 * A156585 A299923 A087358
Adjacent sequences: A159608 A159609 A159610 * A159612 A159613 A159614


KEYWORD

nonn,more


AUTHOR

Walter Nissen, Apr 16 2009


STATUS

approved



