Problem Statement

Compute the   nth   term of a series,   i.e. the sum of the   n   first terms of the corresponding sequence.
Informally this value, or its limit when   n   tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use:

This approximates the   zeta function   for   S=2,   whose exact value is the solution of the Basel problem.

Let's start with the solution:

{+ {S.map {lambda {:k} {/ 1 {* :k :k}}} {S.serie 1 1000}}}
-> 1.6439345666815615 ~  1.6449340668482264 = PI^2/6