Code Golf: Prime Factors of a Number [closed]

Answer 1

F#

81 chars

let rec f n=if n=1 then[]else let a=[2..n]|>List.find(fun x->n%x=0)in a::f(n/a)

It's terribly inefficient, but since the aim is undoubtedly to write the shortest code possible, I've neglected that matter.

Readable form (using #light syntax):

let rec factorise n =
    if n = 1 then [] else
    let a = [2 .. n] |> List.find (fun x -> n % x = 0)
    a :: factorise (n / a)