Objective Caml version 3.07+2

let n = 16
let rec loopF x = function 0 -> x | i -> loopF (x+1) (i-1)
let rec loopE x = function 0 -> x | i -> loopE (loopF x n) (i-1)
let rec loopD x = function 0 -> x | i -> loopD (loopE x n) (i-1)
let rec loopC x = function 0 -> x | i -> loopC (loopD x n) (i-1)
let rec loopB x = function 0 -> x | i -> loopB (loopC x n) (i-1)
let rec loopA x = function 0 -> x | i -> loopA (loopB x n) (i-1);;
Printf.printf "%d\n" (loopA 0 n)

=> 0.054 / ruby 1.8.1 (2003-12-25) [powerpc-darwin]