A033844 a(n) = prime(2^n).

2, 3, 7, 19, 53, 131, 311, 719, 1619, 3671, 8161, 17863, 38873, 84017, 180503, 386093, 821641, 1742537, 3681131, 7754077, 16290047, 34136029, 71378569, 148948139, 310248241, 645155197, 1339484197, 2777105129, 5750079047, 11891268401, 24563311309, 50685770167, 104484802057, 215187847711

Offset: 0

Author

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

Keywords

• nonn
• hard

Comments

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

Links

• David Baugh, Table of n, a(n) for n = 0..78 (terms n = 0..57 from Charles R Greathouse IV, terms n = 58..78 found using Kim Walisch's primecount program).

Crossrefs

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

Programs

Mathematica

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

PARI

a(n)=prime(2^n) \\ Charles R Greathouse IV, Nov 02 2014

Extensions

More terms from Robert G. Wilson v, Jun 09 2000