Col

  import java.util.Scanner;
    
    public class col 
    {
        
        public static void main( String[] args )
        {
            
            Scanner keyboard = new Scanner(System.in);
            
            int n;
            
            System.out.print( "Starting number: " );
            n = keyboard.nextInt();
            System.out.print( n );
            
            while ( n != 1 )
            {
                
                if ( n % 2 == 0 ) 
                {
                    n = n / 2;
                }
                
                else if ( n % 2 != 0 ) 
                {
                    n = ( 3 * n ) + 1;
                }
                
                System.out.print( "\t" + n );    
            }
            System.out.println();
        }
    }
    

Picture of the output