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A160400 a(n) = the smallest positive integer such that a(n)*n = j^k, for some j (j>=1) and k (k>=2). 3
1, 2, 3, 1, 5, 6, 7, 1, 1, 10, 11, 3, 13, 14, 15, 1, 17, 2, 19, 5, 21, 22, 23, 6, 1, 26, 1, 7, 29, 30, 31, 1, 33, 34, 35, 1, 37, 38, 39, 10, 41, 42, 43, 11, 5, 46, 47, 3, 1, 2, 51, 13, 53, 4, 55, 14, 57, 58, 59, 15, 61, 62, 7, 1, 65, 66, 67, 17, 69, 70, 71, 2, 73, 74, 3, 19, 77, 78, 79, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = A087320(n)/n.

a(n) = A007913(n) for n cubefree, a(n) = 1 for n in A001597. - Charlie Neder, Dec 26 2018

LINKS

Table of n, a(n) for n=1..80.

MAPLE

isA001597 := proc(n) local e, p ; if n = 1 then RETURN(true) ; fi; p := [] ; for e in ifactors(n)[2] do p := [op(p), op(2, e) ] ; od: if igcd(op(p)) > 1 then true; else false; fi; end: A160400 := proc(n) local a; for a from 1 do if isA001597(a*n) then RETURN(a) ; fi; od: end: seq(A160400(n), n=1..120) ; # R. J. Mathar, May 26 2009

CROSSREFS

Cf. A087320, A001597, A007913.

Sequence in context: A055231 A304328 A304339 * A072400 A007913 A083346

Adjacent sequences:  A160397 A160398 A160399 * A160401 A160402 A160403

KEYWORD

nonn

AUTHOR

Leroy Quet, May 12 2009

EXTENSIONS

More terms from R. J. Mathar, May 26 2009

STATUS

approved

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Last modified March 18 22:11 EDT 2019. Contains 321305 sequences. (Running on oeis4.)