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A076397
Largest prime factor of n-th perfect power.
3
1, 2, 2, 3, 2, 5, 3, 2, 3, 7, 2, 3, 5, 11, 5, 2, 3, 13, 7, 3, 5, 3, 2, 17, 3, 7, 19, 5, 7, 11, 2, 23, 3, 5, 13, 3, 7, 29, 5, 31, 5, 2, 11, 17, 7, 3, 11, 37, 19, 13, 5, 41, 3, 7, 43, 11, 5, 2, 23, 3, 13, 47, 3, 7, 5, 17, 13, 7, 53, 3, 11, 5, 7, 19, 29, 5, 59, 5, 61, 31, 7, 2, 13, 11, 67, 17, 23
OFFSET
1,2
COMMENTS
a(n) = A006530(A001597(n)).
LINKS
Eric Weisstein's World of Mathematics, Perfect Powers.
Eric Weisstein's World of Mathematics, Greatest Prime Factor.
FORMULA
a(n) = A006530(A025478(n)).
MATHEMATICA
perfPQ[n_]:=GCD@@FactorInteger[n][[All, 2]]>1; Join[ {1}, FactorInteger[ #][[-1, 1]]&/@ Select[Range[5000], perfPQ]] (* Harvey P. Dale, Sep 12 2021 *)
PROG
(Haskell)
a076397 = a006530 . a025478 -- Reinhard Zumkeller, Mar 28 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 09 2002
STATUS
approved