Sucesión de Fibonacci - 2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Fibonacci_4
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{

for (int i = 0; i <= 25; i++)
{
listBox1.Items.Add(fibonaci(i).ToString());
}
}
static int fibonaci(int x)
{
if (x <= 1)
return 1;
return fibonaci(x - 1) + fibonaci(x - 2);
}



private void button2_Click(object sender, EventArgs e)
{
Application.Exit();
}
}
}

https://es.wikipedia.org/wiki/Sucesi%C3%B3n_de_Fibonacci
http://jcastrom.jimdo.com/inform%C3%A1tica/la-serie-de-fibonacci/