0,2

For 2n = 20, we get a negative value -2830020810398. This seems strange to me.

I emailed Marc Deleglise on this. The links shows the Pi(x) and SumP(x) values.

Table of n, a(n) for n=0..11.

Cino Hilliard, Comparison of Pi(x^2) and SumP(x).

Pi(x) is the prime counting function or the number of primes <= x. SumP(x) = sum of primes <= x.

Cf. A046731, A000720, A006880.

Sequence in context: A254459 A254129 A084941 * A264113 A181198 A302802

Adjacent sequences: A139561 A139562 A139563 * A139565 A139566 A139567

sign

Cino Hilliard, Jun 11 2008

approved