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!)
A086411 Greatest prime factor of 3-smooth numbers. 6
1, 2, 3, 2, 3, 2, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = A006530(A003586(n)).
A086410(n) <= a(n) <= 3.
a(A033845(n)) = A086410(A033845(n))+1; a(A006899(n)) = A086410(A006899(n)). - Reinhard Zumkeller, Sep 25 2008
MATHEMATICA
Reap[Do[p = FactorInteger[n][[-1, 1]]; If[p < 5, Sow[p]], {n, 1, 2*10^5}] ][[2, 1]] (* Jean-François Alcover, Dec 17 2017 *)
CROSSREFS
Sequence in context: A304097 A251101 A065067 * A105528 A076225 A215776
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 18 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.)