The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A074767 Least m>n with spf(m)=gpf(n), where gpf(n) is the greatest prime factor of n and spf(m) is the smallest prime factor of m. 0
 4, 9, 6, 25, 9, 49, 10, 15, 25, 121, 15, 169, 49, 25, 18, 289, 21, 361, 25, 49, 121, 529, 27, 35, 169, 33, 49, 841, 35, 961, 34, 121, 289, 49, 39, 1369, 361, 169, 55, 1681, 49, 1849, 121, 55, 529, 2209, 51, 77, 55, 289, 169, 2809, 57, 121, 77, 361, 841, 3481, 65 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n)=gpf(n)^2 for n n/gpf(n)). LINKS MATHEMATICA mfs={#, First[FactorInteger[#]][[1]]}&/@Range[3500]; Table[Select[Select[mfs, #[[2]]==Last[FactorInteger[n]][[1]]&], #[[1]]>n&][[1, 1]], {n, 2, 60}]  (* Harvey P. Dale, Feb 18 2011 *) CROSSREFS Cf. A006530, A020639, A064052, A048098, A007918. Sequence in context: A140694 A152454 A287932 * A016097 A083717 A332451 Adjacent sequences:  A074764 A074765 A074766 * A074768 A074769 A074770 KEYWORD nonn AUTHOR Reinhard Zumkeller, Sep 29 2002 EXTENSIONS Corrected by Harvey P. Dale, Feb 18 2011 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 30 15:29 EDT 2021. Contains 346359 sequences. (Running on oeis4.)