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A304328 a(n) = n/(largest perfect power divisor of n). 4
1, 2, 3, 1, 5, 6, 7, 1, 1, 10, 11, 3, 13, 14, 15, 1, 17, 2, 19, 5, 21, 22, 23, 3, 1, 26, 1, 7, 29, 30, 31, 1, 33, 34, 35, 1, 37, 38, 39, 5, 41, 42, 43, 11, 5, 46, 47, 3, 1, 2, 51, 13, 53, 2, 55, 7, 57, 58, 59, 15, 61, 62, 7, 1, 65, 66, 67, 17, 69, 70, 71, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Not all terms are squarefree numbers; for example, a(500) = 4.

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1000

FORMULA

a(n) * A203025(n) = n.

MATHEMATICA

Table[n/Last[Select[Divisors[n], #===1||GCD@@FactorInteger[#][[All, 2]]>1&]], {n, 100}]

PROG

(PARI) a(n)={my(m=1); fordiv(n, d, if(ispower(d), m=max(m, d))); n/m} \\ Andrew Howroyd, Aug 26 2018

CROSSREFS

Cf. A000961, A001055, A001222, A001597, A001694, A005117, A007716, A007916, A052485, A052486, A059404, A066636, A091050, A160400, A203025, A294068, A303707, A304327, A304339.

Sequence in context: A130508 A182938 A055231 * A304339 A160400 A072400

Adjacent sequences:  A304325 A304326 A304327 * A304329 A304330 A304331

KEYWORD

nonn

AUTHOR

Gus Wiseman, May 10 2018

STATUS

approved

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Last modified March 24 00:12 EDT 2019. Contains 321444 sequences. (Running on oeis4.)