A228065 Difference of consecutive integers nearest to (10^n)/log(10^n) (A057834).

4, 18, 123, 941, 7600, 63696, 548039, 4808260, 42826261, 386039540, 3513837172, 32243075171, 297881471562, 2768030763779, 25850862018051, 242481085729315, 2283239371770773, 21572797793887019, 204448571890127322, 1942896366409284492

Offset: 1

Author

Vladimir Pletser, Aug 06 2013

Keywords

• nonn

Comments

This sequence gives an approximation of the number of primes with n digits (A006879); see A228066.

Note that A057834(n) = (10^n)/log(10^n) is not defined for n=0. Its value is set arbitrarily to 0.

Examples

			For n = 1, A057834(1) - A057834(0) = 4-0 = 4.
		

Links

• Vladimir Pletser, Table of n, a(n) for n = 1..500
• Eric Weisstein's World of Mathematics, Prime Counting Function.

Crossrefs

Cf. A006879, A057834, A228066.

Formula

a(n) = A057834(n) - A057834(n-1).