Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A062563
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A062563 Sum_{k=1...n} d(k)* mu(k), where d(k) is the number of divisors function. +0
2
1, -1, -3, -3, -5, -1, -3, -3, -3, 1, -1, -1, -3, 1, 5, 5, 3, 3, 1, 1, 5, 9, 7, 7, 7, 11, 11, 11, 9, 1, -1, -1, 3, 7, 11, 11, 9, 13, 17, 17, 15, 7, 5, 5, 5, 9, 7, 7, 7, 7, 11, 11, 9, 9, 13, 13, 17, 21, 19, 19, 17, 21, 21, 21, 25, 17, 15, 15, 19, 11, 9, 9, 7, 11, 11, 11, 15, 7, 5, 5, 5, 9, 7, 7, 11, 15, 19, 19, 17, 17, 21, 21, 25, 29, 33, 33, 31 (list; graph; listen)
OFFSET

1,3

FORMULA

Also a(n)=sum(k=1,n,2^omega(k)*mu(k)) - Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 13 2007

PROGRAM

(PARI) v=[]; for(n=1, 250, v=concat(v, sum(k=1, n, numdiv(k)*moebius(k)))); v

CROSSREFS

Sequence in context: A103786 A067462 A021753 this_sequence A091931 A109824 A011399

Adjacent sequences: A062560 A062561 A062562 this_sequence A062564 A062565 A062566

KEYWORD

sign

AUTHOR

Jason Earls (zevi_35711(AT)yahoo.com), Jul 03 2001

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.


AT&T Labs Research