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A072814
Smallest exponents of perfect powers: A001597(n)=A072813(n)^a(n).
1
2, 2, 3, 2, 2, 2, 3, 5, 2, 2, 2, 2, 2, 2, 3, 7, 2, 2, 2, 3, 2, 5, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 11, 2, 7, 3, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 5, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Perfect Power.
MATHEMATICA
{2}~Join~Map[Function[m, Min@ DeleteCases[#, x_ /; x < 2] &@ Table[Boole[k^# == m] # &@ IntegerExponent[m, k], {k, 2, Floor@ Sqrt@ m}]], Select[Range@ 5000, GCD @@ FactorInteger[#][[All, -1]] > 1 &]] (* Michael De Vlieger, Dec 08 2016 *)
CROSSREFS
Sequence in context: A160821 A300225 A060244 * A196229 A191302 A161189
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 12 2002
EXTENSIONS
Definition corrected by Daniel Forgues, Mar 07 2009
Inserted a(1) = 2 by Gionata Neri, Dec 08 2016
STATUS
approved