Problem Statement

Find an approximating polynomial of known degree for a given data. Example: For input data: The approximating polynomial is: Here, the polynomial's coefficients are (3, 2, 1). This task is intended as a subtask for Measure relative performance of sorting algorithms implementations.

Let's start with the solution:

   Y=:1 6 17 34 57 86 121 162 209 262 321
   (%. ^/~@x:@i.@#) Y
1 2 3 0 0 0 0 0 0 0 0


   Y %. (i.3) ^/~ i.#Y
1 2 3