Catalan Numbers

/*Catalan Numbers are the numbers of the form:
(2n)!/((n!)^2*(n+1))*/
import java.util.Scanner;
class Catalan
{
public static void main(String[ ] args)
{
    Scanner in=new Scanner (System.in);
    System.out.println("Enter value of n(1...10):");
    int n=in.nextInt();
    long n1,n2,a;
    long CatNumber;
    int cnt=1;
    if(n>=1 && n<=10)
    {
        for(a=1;a<=n;a++)
        {
            long factofa=1,factof2a=1;
            for(long i=1;i<=a;i++)
            factofa*=i;
            for(long i=1;i<=2*a;i++)
            factof2a*=i;
            CatNumber=factof2a/((factofa*factofa)*(a+1));
            System.out.println(" "+cnt++ +". "+CatNumber);
        }
    }
}
}