login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A052126 a(1) = 1; for n>1, a(n)=n/(largest prime dividing n). 47

%I

%S 1,1,1,2,1,2,1,4,3,2,1,4,1,2,3,8,1,6,1,4,3,2,1,8,5,2,9,4,1,6,1,16,3,2,

%T 5,12,1,2,3,8,1,6,1,4,9,2,1,16,7,10,3,4,1,18,5,8,3,2,1,12,1,2,9,32,5,

%U 6,1,4,3,10,1,24,1,2,15,4,7,6,1,16,27,2,1,12,5,2,3,8,1,18,7,4,3,2,5,32,1

%N a(1) = 1; for n>1, a(n)=n/(largest prime dividing n).

%C For n>1, a(n)=1 if and only if n is prime. - _Zak Seidov_, Feb 09 2015

%H R. Zumkeller, <a href="/A052126/b052126.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = n/A006530(n).

%F a(n) = A130065(n)/A020639(n). - _Reinhard Zumkeller_, May 05 2007

%e a(15) = 15/(largest prime dividing 15) = 15/5 = 3.

%p a := n -> `if`(n=1, 1, n/max(numtheory[factorset](n)));

%p seq(a(n), n=1..97); # _Peter Luschny_, Jul 28 2014

%t a052126[n_] := Array[If[n == 1, 1, #/FactorInteger[#][[-1]][[1]]] &, n]; a052126[97] (* _Michael De Vlieger_, Dec 21 2014 *)

%o (PARI) gpf(n)=my(f=factor(n)[,1]); f[#f]

%o a(n)=if(n<4,return(1)); n/gpf(n) \\ _Charles R Greathouse IV_, Apr 28 2015

%Y Cf. A000040, A006530, A032742, A130065, A020639.

%K nonn,look

%O 1,4

%A _James A. Sellers_, Jan 21 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 13 19:41 EST 2018. Contains 318087 sequences. (Running on oeis4.)