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Revision History for A136567

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A136567

a(n) is the number of exponents occurring only once each in the prime factorization of n.
(history; published version)

#19 by N. J. A. Sloane at Wed Jul 26 09:23:41 EDT 2017

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proposed

approved

#18 by Michel Marcus at Wed Jul 26 05:18:01 EDT 2017

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editing

proposed

#17 by Michel Marcus at Wed Jul 26 05:17:53 EDT 2017

NAME

a(n) = is the number of exponents occurring only once each in the prime factorization of n.

STATUS

proposed

editing

#16 by Jon E. Schoenfield at Mon Jul 24 21:55:18 EDT 2017

STATUS

editing

proposed

#15 by Jon E. Schoenfield at Mon Jul 24 21:55:15 EDT 2017

NAME

a(n) = number of exponents occurring only once each in the prime- factorization of n.

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proposed

editing

#14 by Michael De Vlieger at Mon Jul 24 17:29:31 EDT 2017

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editing

proposed

#13 by Michael De Vlieger at Mon Jul 24 17:29:25 EDT 2017

MATHEMATICA

Table[Boole[n != 1] Count[Split@ Sort[FactorInteger[n][[All, -1]]], _?(Length@ # == 1 &)], {n, 105}] (* Michael De Vlieger, Jul 24 2017 *)

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proposed

editing

#12 by Michel Marcus at Mon Jul 24 16:22:47 EDT 2017

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editing

proposed

#11 by Michel Marcus at Mon Jul 24 16:22:37 EDT 2017

MATHEMATICA

f[n_] := Block[{fi = Sort[Last /@ FactorInteger@n]}, Count[ Count[fi, # ] & /@ Union@fi, 1]]; f[1] = 0; Array[f, 105] - _(* _Robert G. Wilson v_, Jan 20 2008 *)

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proposed

editing

#10 by Antti Karttunen at Mon Jul 24 16:21:59 EDT 2017

STATUS

editing

proposed