Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
f(n+1)=(2-1/n)f(n)-f(n-1), f(2)=1, f(1)=0
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
