John, I don't know what functional code is. However the following example shows the calculation of the product of successive odd numbers for quite a range. What kind of code is it? Jerry >> source test test: func [n /local x z][ x: array 0 for i 1 n 1 [insert x 2 * i + 1] z: 1 for i 1 n 1 [z: z * pick x i] ] >> test 9 == 654729075 >> test 149 == 3.75327411157192E+306 >>