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!)
A073764 a(n) = least number x such that A045763(x)=n or 0 if no such number exists. 0
6, 0, 10, 15, 14, 21, 18, 35, 22, 33, 26, 39, 0, 65, 30, 36, 38, 57, 44, 95, 46, 63, 42, 115, 50, 64, 58, 87, 54, 75, 68, 155, 60, 99, 74, 111, 72, 185, 66, 117, 86, 129, 92, 215, 94, 141, 78, 235, 84, 105, 98, 100, 96, 265, 90, 135, 118, 147, 122, 183, 108, 305, 102 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
A070297 without its term a(0). [From R. J. Mathar, Sep 23 2008]
LINKS
EXAMPLE
A045763(x)=5 first holds if x=14 because unrelated set of 14={4,6,8,10,12} has 5 entries. No solutions were found for n=2,13,67,93 when tested at <100000.
MATHEMATICA
t=Table[0, {100}]; Do[s=n+1-DivisorSigma[0, n]-EulerPhi[n]; If[s<101&&t[[s]]==0, t[[s]]=n], {n, 1, 100000}]; t
CROSSREFS
Sequence in context: A083573 A117006 A294345 * A158897 A033458 A068308
KEYWORD
nonn
AUTHOR
Labos Elemer, Aug 08 2002
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 April 24 06:39 EDT 2024. Contains 371920 sequences. (Running on oeis4.)