list of factors [was: Maple question]

[Eric W. Weisstein]

On Sat, 1 May 2004, Emeric Deutsch wrote:

> Dear Seqfans,
> I wonder whether this is an appropriate topic.
> Let me formulate my simple question on an example.
> The command ifactor(72) yields 2^3 3^2.
> I would like to get [2,2,2,3,3].
> Any idea? Thanks.
> Emeric 

On Sat, 1 May 2004, N. J. A. Sloane wrote:

> > ifactors(72);
>                                             [1, [[2, 3], [3, 2]]]
> 
> is as close as you can get - but that's pretty close!
> 
> Emeric asked:
> The command ifactor(72) yields 2^3 3^2.
> I would like to get [2,2,2,3,3].

In Mathematica:

Flatten[Table[#1,{#2}]& @@@ FactorInteger[72]]
  or
Flatten[Table[#[[1]], {#[[2]]}]& /@ FactorInteger[72]]
  or
Flatten[Table[First[#],{Last[#]}]& /@ FactorInteger[72]]

{2,2,2,3,3} 

Cheers,
-Eric