A076397 Largest prime factor of n-th perfect power.

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

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

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

Cf. A025478, A076396, A076403.

Sequence in context: A258567 A076396 A370834 * A254269 A264662 A076403

Adjacent sequences: A076394 A076395 A076396 * A076398 A076399 A076400

Keyword

nonn

Author

Reinhard Zumkeller, Oct 09 2002

Status

approved