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A228065 Difference of consecutive integers nearest to (10^n)/log(10^n) (A057834). 3
4, 18, 123, 941, 7600, 63696, 548039, 4808260, 42826261, 386039540, 3513837172, 32243075171, 297881471562, 2768030763779, 25850862018051, 242481085729315, 2283239371770773, 21572797793887019, 204448571890127322, 1942896366409284492 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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.

LINKS

Vladimir Pletser, Table of n, a(n) for n = 1..500

Eric Weisstein's World of Mathematics, Prime_counting_function

FORMULA

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

EXAMPLE

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

CROSSREFS

Cf. A006879, A057834, A228066.

Sequence in context: A084661 A112294 A292500 * A317377 A215691 A073511

Adjacent sequences:  A228062 A228063 A228064 * A228066 A228067 A228068

KEYWORD

nonn

AUTHOR

Vladimir Pletser, Aug 06 2013

STATUS

approved

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Last modified February 20 14:14 EST 2020. Contains 332078 sequences. (Running on oeis4.)