This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A073752 Greatest common divisor of n/spf(n) and n/gpf(n) where spf(n) is the smallest and gpf(n) is the greatest prime factor of n (see A020639, A006530). 3
 1, 1, 1, 2, 1, 1, 1, 4, 3, 1, 1, 2, 1, 1, 1, 8, 1, 3, 1, 2, 1, 1, 1, 4, 5, 1, 9, 2, 1, 3, 1, 16, 1, 1, 1, 6, 1, 1, 1, 4, 1, 3, 1, 2, 3, 1, 1, 8, 7, 5, 1, 2, 1, 9, 1, 4, 1, 1, 1, 6, 1, 1, 3, 32, 1, 3, 1, 2, 1, 5, 1, 12, 1, 1, 5, 2, 1, 3, 1, 8, 27, 1, 1, 6, 1, 1, 1, 4, 1, 9, 1, 2, 1, 1, 1, 16, 1, 7, 3, 10, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS a(n) = if n=p^k (p prime, k>0) then p^(k-1) else n/(spf(n)*gpf(n)). LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA a(n) = GCD(A032742(n), A052126(n)). MATHEMATICA gc[n_]:=Module[{fi=Transpose[FactorInteger[n]][[1]]}, GCD[n/First[fi], n/Last[ fi]]]; Array[gc, 110] (* Harvey P. Dale, Jun 17 2012 *) CROSSREFS Cf. A000961, A066048. A073753(n) = a(a(n)). Sequence in context: A000189 A000190 A003557 * A128708 A087653 A295666 Adjacent sequences:  A073749 A073750 A073751 * A073753 A073754 A073755 KEYWORD nonn AUTHOR Reinhard Zumkeller, Aug 07 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 | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 14 11:04 EST 2018. Contains 317182 sequences. (Running on oeis4.)