The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A081247 Number of numbers k<=n with mu(k+n)=mu(k), where mu=A008683 (Moebius function). 1
0, 0, 1, 2, 3, 1, 0, 5, 4, 3, 3, 7, 2, 4, 4, 10, 3, 6, 5, 12, 4, 3, 6, 16, 9, 6, 7, 13, 10, 10, 7, 16, 6, 9, 8, 25, 9, 9, 10, 22, 13, 13, 12, 19, 10, 9, 16, 29, 10, 16, 14, 24, 10, 21, 17, 31, 9, 13, 20, 37, 16, 14, 18, 30, 18, 20, 21, 35, 13, 16, 27, 49, 21, 15, 13, 42, 22, 25, 19, 39, 26 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
LINKS
EXAMPLE
n=10: mu(3+10)=mu(3)=-1, mu(7+10)=mu(7)=-1, mu(8+10)=mu(8)=0 and mu(k+10)<>mu(k) for k in {1,2,4,5,6,8,9}, therefore a(10)=3.
CROSSREFS
Cf. A081248.
Sequence in context: A193535 A332645 A344855 * A298753 A173050 A172380
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Mar 12 2003
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 17 19:53 EDT 2024. Contains 372607 sequences. (Running on oeis4.)