PrimePi

The prime-counting function: how many primes are ≤ n.

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PrimePi(n)count of primes .

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Domain: Number theory

Details

Inverse of NthPrime: .
Asymptotically , the prime number theorem.
n need not be an integer or prime itself -- PrimePi(n) counts primes up to whatever real value is given.
compute-engine does not.

Examples

See also: NthPrime, NextPrime