import java.util.Scanner;

/** Formula.java - Example program illustrating how to use recursion
 *  in simple examples involving some recursive formula.
 *  Note that in each recursive function there is a base case, and
 *  a recursive case.  We need the base case to know when the recursion stops.
 */
public class Formula
{
  public static void main(String [] args)
  {
    System.out.print("Enter a positive integer:  ");
    Scanner kbd = new Scanner(System.in);
    int a = Integer.parseInt(kbd.nextLine());

    System.out.printf("Odd number # %d is %d\n", a, odd(a));
    System.out.printf("%d factorial is %d\n", a, fact(a));
    System.out.printf("Term # %d in Fibonacci sequence is %d\n", a, fib(a));
  }

  public static int odd(int n)
  {
    if (n == 1)
      return 1;
    else
      return 2 + odd(n-1);
  }

  public static int fact(int n)
  {
    if (n == 0)
      return 1;
    else
      return n * fact(n-1);
  }

  public static int fib(int n)
  {
    if (n <= 2)
      return 1;
    else
      return fib(n-1) + fib(n-2);
  }
}