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 March 19 03:33 EDT 2024. Contains 370952 sequences. (Running on oeis4.)