login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A064016 a(n) = sum_{k <= 10^n} cototient(k), where cototient is A051953. 0
0, 23, 2006, 196308, 19607514, 1960399246, 196036947608, 19603648572758, 1960364533634092, 196036449326991586, 19603644912113783634, 1960364490766613788860, 196036449073440195974090 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Conjecture: It would appear that the sum from 1 to n approaches the limit 0.1960364...*n^2 = (1/2 - 3/Pi^2)*n^2.

LINKS

Table of n, a(n) for n=0..12.

MATHEMATICA

s = 0; k = 1; Do[ While[ k <= 10^n, s = s + k - EulerPhi[ k ]; k++ ]; Print[ s ], {n, 0, 8} ]

CROSSREFS

Cf. A002088, A051953, A063986.

Sequence in context: A319508 A269122 A132395 * A263462 A138735 A220653

Adjacent sequences:  A064013 A064014 A064015 * A064017 A064018 A064019

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 07 2001

EXTENSIONS

a(9) from Jud McCranie, Jun 25 2005

a(10)-a(11) from Donovan Johnson, Feb 06 2010

a(12) from Donovan Johnson, Feb 07 2012

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 05:51 EDT 2019. Contains 327212 sequences. (Running on oeis4.)