Problem Statement

Catalan numbers are a sequence of numbers which can be defined directly: Or recursively: Or alternatively (also recursive):

Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above.

Let's start with the solution:

$ include "seed7_05.s7i";
  include "bigint.s7i";

const proc: main is func
  local
    var bigInteger: n is 0_;
  begin
    for n range 0_ to 15_ do
      writeln((2_ * n) ! n div succ(n));
    end for;
  end func;