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a(n) = prime(2^n).
64

%I #33 Oct 04 2020 23:36:40

%S 2,3,7,19,53,131,311,719,1619,3671,8161,17863,38873,84017,180503,

%T 386093,821641,1742537,3681131,7754077,16290047,34136029,71378569,

%U 148948139,310248241,645155197,1339484197,2777105129,5750079047,11891268401,24563311309,50685770167,104484802057,215187847711

%N a(n) = prime(2^n).

%C a(n) is the smallest number m such that pi(m)=d(m)^n, where d(m) is number of positive divisors of m (the proof is easy). - _Farideh Firoozbakht_, Jun 06 2005

%H David Baugh, <a href="/A033844/b033844.txt">Table of n, a(n) for n = 0..78</a> (terms n = 0..57 from Charles R Greathouse IV, terms n = 58..78 found using Kim Walisch's primecount program).

%t Table[Prime[2^n], {n, 0, 32}]

%o (PARI) a(n)=prime(2^n) \\ _Charles R Greathouse IV_, Nov 02 2014

%Y Cf. A000040, A018249, A051438, A051440, A051439, A006988, A107655.

%K nonn,hard

%O 0,1

%A Vasiliy Danilov (danilovv(AT)usa.net), Jun 15 1998

%E More terms from _Robert G. Wilson v_, Jun 09 2000