Re: Re: The prime factors of n.

*To*: mathgroup at smc.vnet.net*Subject*: [mg32784] Re: [mg32748] Re: [mg32673] The prime factors of n.*From*: "Peter Bertok" <peter at bertok.com>*Date*: Sat, 9 Feb 2002 05:12:08 -0500 (EST)*References*: <200202060841.DAA02157@smc.vnet.net> <200202080849.DAA11933@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

> > I wish to receive a list of prime factors of n not in the form > > returned by FactorInteger. Instead I want only the primes the number of > > times they appear. As an example I will use 72. FactorInteger[72] gives > > { {2,3}, {3,2} }. I wish the list would read { 2, 2, 2, 3, 3 }. Is the > > following the best that I can do? f[n_Integer] := Module[{a = > > FactorInteger[n], b = {}}, While[Length[a] > 0, Do[b = Append[b, a[[1, > > 1]]], {a[[1, 2]]}]; a = Drop[a, 1]]; b] . > > > > See > > http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cg i?Anum=037276 > > Also: f[n_] := Flatten[Table[First[#], {Last[#]}] & /@ FactorInteger[n]]

**References**:**The prime factors of n.***From:*"Robert G. Wilson v" <rgwv@kspaint.com>

**Re: The prime factors of n.***From:*Ken Levasseur <Kenneth_Levasseur@uml.edu>