A071973 Number of primes less than or equal to Pi^n.

0, 2, 4, 11, 25, 62, 162, 433, 1175, 3229, 9042, 25549, 73050, 210356, 610041, 1779830, 5218745, 15372304, 45455747, 134882577, 401480918, 1198344171, 3585783711, 10754085805, 32319203663, 97312548674, 293515297707, 886720888966, 2682778745396, 8127887397064

Offset: 0

Author

Robert G. Wilson v, Jun 18 2002

Keywords

• hard
• nonn

Links

• David Baugh, Table of n, a(n) for n = 0..52 (terms n = 27..52 found using Kim Walisch's primecount program)
• Index entries for sequences related to numbers of primes in various ranges

Crossrefs

Cf. A000720, A001672, A061274.

Programs

Mathematica

Do[ Print[ PrimePi[Pi^n]], {n, 0, 28}]

PARI

a(n) = primepi(Pi^n); \\ Michel Marcus, Oct 05 2020

Formula

a(n) = A000720(A001672(n)). - Michel Marcus, Oct 05 2020

Extensions

a(27)-a(29) from David Baugh, Oct 05 2020