The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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 Cf. A006879, A057793, A228111 - A228116. Sequence in context: A050910 A220378 A230645 * A306589 A221513 A284231 Adjacent sequences:  A228110 A228111 A228112 * A228114 A228115 A228116 KEYWORD nonn AUTHOR Vladimir Pletser, Aug 10 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 18 01:05 EST 2020. Contains 330995 sequences. (Running on oeis4.)