A139564 Number of primes < 10^(2n) - sum of primes < 10^n.

0, 8, 169, 2371, 25059, 655974, 57509995, 1616756446, 28550646649, 442195486325, -2830020810398, 208945571225276, 11214798494956489, 307494657722438109, 8565236469871178577

Offset

0,2

Comments

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

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.

Links

Table of n, a(n) for n=0..14.

Cino Hilliard, Comparison of Pi(x^2) and SumP(x). [broken link]

Formula

a(n) = A006880(2*n) - A046731(n). - Amiram Eldar, Jun 30 2024

Crossrefs

Cf. A000720, A006880, A046731.

Sequence in context: A359926 A334780 A084941 * A264113 A181198 A302802

Adjacent sequences: A139561 A139562 A139563 * A139565 A139566 A139567

Keyword

sign,more,changed

Author

Cino Hilliard, Jun 11 2008

Extensions

a(12)-a(14) from Amiram Eldar, Jun 30 2024

Status

approved