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A072375 Number of cubefree numbers <= n which are nonsquares having exactly one square in their factorization. 1
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 6, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 15 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,18

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

cfnsQ[n_]:=Module[{f=FactorInteger[n][[All, 2]]}, Max[f]<3&&Count[f, 2] == 1&&!IntegerQ[Sqrt[n]]]; Accumulate[Table[If[cfnsQ[n], 1, 0], {n, 100}]] (* Harvey P. Dale, May 24 2017 *)

CROSSREFS

Cf. A072358, A060431.

Sequence in context: A140474 A091195 A280617 * A131981 A257244 A130147

Adjacent sequences:  A072372 A072373 A072374 * A072376 A072377 A072378

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 19 2002

STATUS

approved

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Last modified June 6 10:47 EDT 2020. Contains 334844 sequences. (Running on oeis4.)