A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.

(Munchausen is also spelled: Münchhausen.)

For instance:    3435 = 33 + 44 + 33 + 55 



Task
Find all Munchausen numbers between   1   and   5000.



Also see

 The OEIS entry:  A046253
 The Wikipedia entry:  Perfect digit-to-digit invariant, redirected from Munchausen Number


let toFloat x = x |> int |> fun n -> n - 48 |> float
let power x = toFloat x ** toFloat x |> int
let isMunchausen n = n = (string n |> Seq.map char |> Seq.map power |> Seq.sum)
 
printfn "%A" ([1..5000] |> List.filter isMunchausen)