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!)
A328479 a(n) = n/A328478(n), where A328478(n) is obtained by repeatedly dividing n by the largest primorial that divides it until a fixed point is reached. 5
1, 2, 1, 4, 1, 6, 1, 8, 1, 2, 1, 12, 1, 2, 1, 16, 1, 6, 1, 4, 1, 2, 1, 24, 1, 2, 1, 4, 1, 30, 1, 32, 1, 2, 1, 36, 1, 2, 1, 8, 1, 6, 1, 4, 1, 2, 1, 48, 1, 2, 1, 4, 1, 6, 1, 8, 1, 2, 1, 60, 1, 2, 1, 64, 1, 6, 1, 4, 1, 2, 1, 72, 1, 2, 1, 4, 1, 6, 1, 16, 1, 2, 1, 12, 1, 2, 1, 8, 1, 30, 1, 4, 1, 2, 1, 96, 1, 2, 1, 4, 1, 6, 1, 8, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) is the largest term in A025487 that divides n evenly. - Hal M. Switkay, May 04 2021
LINKS
FORMULA
a(n) = n / A328478(n).
MATHEMATICA
A111701[n_] := A111701[n] = Block[{m = n, k = 1}, While[IntegerQ[m/Prime[k]], m = m/Prime[k]; k++]; m];
A328478[n_] := If[A111701[n] == n, n, A328478[A111701[n]]];
A328479[n_] := n/A328478[n];
Array[A328479, 105] (* Jean-François Alcover, Jan 11 2022, after Robert G. Wilson v in A111701 *)
PROG
(PARI)
A111701(n) = forprime(p=2, , if(n%p, return(n), n /= p));
A328478(n) = { my(u=A111701(n)); if(u==n, return(n), return(A328478(u))); };
A328479(n) = (n/A328478(n));
CROSSREFS
Sequence in context: A318441 A161510 A329379 * A340346 A193267 A327832
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 19 2019
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 15 13:47 EDT 2024. Contains 371689 sequences. (Running on oeis4.)