#Small Basic, 45 bytes

A script which takes no input and outputs to the TextWindow console.

n=n+1
TextWindow.Clear()
TextWindow.Write(n)

Try it at SmallBasic.com

n=n+1
TextWindow.Clear()
TextWindow.Write(n)
n=n+1
TextWindow.Clear()
TextWindow.Write(n)

Try it Doubled at SmallBasic.com

SmallBasic.com depends on Silverlight, and thus the links must be opened in IE to function.

Small Basic, 45 bytes

A script which takes no input and outputs to the TextWindow console.

n=n+1
TextWindow.Clear()
TextWindow.Write(n)

Try it at SmallBasic.com

n=n+1
TextWindow.Clear()
TextWindow.Write(n)
n=n+1
TextWindow.Clear()
TextWindow.Write(n)

Try it Doubled at SmallBasic.com

SmallBasic.com depends on Silverlight, and thus the links must be opened in IE to function.