The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A229523 Partial sum of the arithmetic derivative A003415 (A190121) up to 10^n. 2
 0, 38, 3906, 386517, 38671110, 3865941752, 386580463478, 38657862140521, 3865783461518530, 386578337105347684, 38657833484501788407, 3865783345588492717623, 386578334529872234861944, 38657833452536035472588254, 3865783345249467526546175599 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Note: A190121 ~ 0.374... * n^2 [Barbeau]. - Giorgio Balzarotti, Oct 15 2013 a(n) ~ 0.386578334524897563932183729927 * 100^n. - Hiroaki Yamanouchi, Jul 09 2014 LINKS Hiroaki Yamanouchi, Table of n, a(n) for n = 0..17 E. J. Barbeau, Remark on an arithmetic derivative, Canad. Math. Bull. vol. 4, no. 2, May 1961. FORMULA a(n) = A190121(10^n). It seems that a(n)/10^(2n-1) -> 3.865783... as n -> oo. PROG (PARI) s=0; for(k=0, 8, for(n=10^(k-1)+1, 10^k, s+=A003415(n)); print1(s", ")); s CROSSREFS Sequence in context: A221111 A322331 A282962 * A173133 A221354 A096558 Adjacent sequences: A229520 A229521 A229522 * A229524 A229525 A229526 KEYWORD nonn,hard AUTHOR M. F. Hasler, Sep 25 2013 EXTENSIONS a(8)-a(10) from Donovan Johnson, Sep 25 2013 a(11)-a(12) from Giovanni Resta, Mar 13 2014 a(13)-a(14) from Hiroaki Yamanouchi, Jul 09 2014 STATUS approved

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

Last modified March 31 17:56 EDT 2023. Contains 361672 sequences. (Running on oeis4.)