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A228113 First differences of A057793. 4
5, 21, 142, 1059, 8360, 68940, 586140, 5096885, 45085903, 404203228, 3663001812, 33489858047, 308457620524, 2858876200536, 26639628764285, 249393770865090, 2344318815695001, 22116397127183516, 209317713015989446, 1986761935255798075, 18906449883376272709 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This sequence is an approximation to the number of primes with n digits (A006879). The error in the approximation is tabulated in A228114.
Because A057793(n) = Riemann(10^n) is not defined for n=0, we set its value to zero for our purpose of defining the differences.
REFERENCES
John H. Conway and R. K. Guy, "The Book of Numbers," Copernicus, an imprint of Springer-Verlag, NY, 1996, page 144-146.
LINKS
Vladimir Pletser, Table of n, a(n) for n = 1..100 [a(40)-a(41) corrected by Sean A. Irvine]
Eric Weisstein's World of Mathematics, Prime Counting Function.
Eric Weisstein's World of Mathematics, Riemann Prime Counting Function.
FORMULA
a(n) = A057793(n) - A057793(n-1).
EXAMPLE
For n=1, A057793(1) - A057793(0) = 5 - 0 = 5.
CROSSREFS
Sequence in context: A050910 A220378 A230645 * A306589 A221513 A284231
KEYWORD
nonn
AUTHOR
Vladimir Pletser, Aug 10 2013
STATUS
approved

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Last modified April 13 10:11 EDT 2024. Contains 371640 sequences. (Running on oeis4.)