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:

$ include "seed7_05.s7i";
  include "float.s7i";

const func float: invsqr (in float: n) is
  return 1.0 / n**2;

const proc: main is func
  local
    var integer: i is 0;
    var float: sum is 0.0;
  begin
    for i range 1 to 1000 do
      sum +:= invsqr(flt(i));
    end for;
    writeln(sum digits 6 lpad 8);
  end func;