Generación de Series

import java.awt.event.*;

import java.awt.*;

import javax.swing.*;

public class Series extends JApplet implements ActionListener{

                // Declaración de variables globales

                JButton btnProcesar, btnBorrar;

                JTextArea txtS;

                JLabel lblNumero ;

                JTextField txtNumero ;

                JScrollPane scpScroll;

               

                // Crea la interfaz gráfica de usuario     

                public void init() {

                               getContentPane().setLayout(null);

                               lblNumero = new JLabel("Numero");

                               lblNumero.setBounds(15, 15, 140, 23);

                               getContentPane().add(lblNumero);

                              

                              

                               txtNumero = new JTextField();

                               txtNumero.setBounds(155, 15, 120, 23);

                               getContentPane().add(txtNumero);

                              

               

                               btnProcesar = new JButton("Procesar");

                               btnProcesar.setBounds(365, 15, 100, 23);

                               btnProcesar.addActionListener(this);

                               getContentPane().add(btnProcesar);

                               txtS = new JTextArea();

                               txtS.setFont(new Font("monospaced", Font.PLAIN, 12));

                              

                               scpScroll = new JScrollPane(txtS);

                               scpScroll.setBounds(15, 77, 450, 150);

                               getContentPane().add(scpScroll);

                }

                // Procesa eventos de tipo ActionEvent

                public void actionPerformed( ActionEvent e ){

                               // Si se hizo clic en Procesar

                               if( e.getSource() == btnProcesar ){

                                              

                                               //Series 01

                                               txtS.setText("Series 01\n");

                                               for(int i =1; i<=30 ;i++){

                                                               txtS.append(i+",");                                                     

                                               }

                                              

                                               //Series 02

                                               txtS.append("\n\nSeries 02\n");

                                               for(int i =5; i<=30 ;i+=2){

                                                               txtS.append(i+",");                                                     

                                               }

                                              

                                               //Series 03

                                               txtS.append("\n\nSeries 03\n");

                                               for(int term =5, c=1; c<=30 ; term+=2, c++){

                                                               txtS.append(term+",");                                                             

                                               }

                                              

                                               //Series 04

                                               // 2/5,  4/8, 6/11, 8/14 ........30terminos

                                               txtS.append("\n\nSeries 04\n");

                                               for(int num =2, den=5, c=1; c<=30 ; num+=2, den+=3, c++){

                                                               txtS.append( num+"/" + den + ",");                                                    

                                               }

                                              

                                               //Series 05

                                               // - Imprima la serie en n terminos

                                               // - Suma la serie

                                               // - El ultimo no termine en coma, sino en punto

                                              

                                               // -2/3,  +6/8, +10/13,  - 14/18,  + 18/23 ........nterminos

                                              

                                               int cantidad = Integer.parseInt(txtNumero.getText());

                                               double suma = 0;

                                               txtS.append("\n\nSeries 05\n");

                                              

                                               for(int num =2, den=3, c=1 ; c<=cantidad ; num+=4, den+=5, c++){

                                                               //signo

                                                               if( (c-1)%3==0 ){

                                                                              txtS.append("-");                                                         

                                                               }else{

                                                                              txtS.append("+");                                                        

                                                               }

                                                               //imprime le numero

                                                               txtS.append( num+"/" + den);                                               

                                                               //la separacion

                                                               if( c == cantidad ){

                                                                              txtS.append(".");                                                         

                                                               }else{

                                                                              txtS.append(",");                                                         

                                                               }

                                                               //signo

                                                               if( (c-1)%3==0 ){

                                                                              suma =  suma  - (1.0)*num/den;

                                                               }else{

                                                                              suma =  suma   +(1.0)*num/den;

                                                               }

                                                              

                                               }

                                              

                                               txtS.append("\nLa suma es : " + suma);

                               }

                              

               

                }

}