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%I #9 Aug 30 2012 11:58:10
%S 0,0,1,4,40,276
%N Number of primes of the form 1 + b^2048 for 1 < b < 10^n.
%C Primes 1 + b^2048 are a form of generalized Fermat primes.
%C It is conjectured that a(n) is asymptotic to 0.00352764*li(10^n)
%H Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/primes/results.html">Status of the smallest base values yielding Generalized Fermat primes</a>
%H Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/primes/stat.html">How many prime numbers appear in a sequence ?</a>
%H Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/papers/ccdgfpn.html">A Problem on the Conjecture Concerning the Distribution of Generalized Fermat Prime numbers (a new method for the search for large primes)</a>
%e a(4) = 4 because the generalized Fermat numbers F_11(b) where b<10^4 are prime only for b = 150, 2558, 4650, 4772.
%o (PARI) a(n) = sum(b=1, 10^n/2-1, isprime((2*b)^2048+1))
%Y Cf. A215047, A215048, A215049, A215050, A215051, A215057, A215058, A215698.
%K nonn
%O 1,4
%A _Henryk Dabrowski_, Aug 21 2012
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