A064151 Number of primes < n^n.

0, 2, 9, 54, 445, 4821, 65685, 1077871, 20700806, 455052511, 11262113374, 309787170203, 9373678643933, 309378125685426, 11059576578724264, 425656284035217743, 17547676024364306476, 771403526860478324343, 36020106660104388871845

Offset: 1

Author

Jason Earls, Sep 13 2001

Keywords

• more
• nonn

Links

• Tomás Oliveira e Silva, Tables of values of pi(x) and of pi2(x) [_Donovan Johnson_, Oct 14 2010]
• Index entries for sequences related to numbers of primes in various ranges

Crossrefs

Cf. A000720, A000312.

Programs

PARI

a(n) = primepi(n^n); \\ Michel Marcus, Apr 18 2018

Formula

a(n) = A000720(A000312(n)). - Michel Marcus, Aug 29 2014

Extensions

a(13)-a(15) from Donovan Johnson, Oct 14 2010

a(16) from Jens Kruse Andersen, Jul 29 2014

a(17)-a(18) from Henri Lifchitz, Aug 29 2014

a(19) from Chai Wah Wu, Apr 18 2018