# Plotting the sequence $u_n = 2u_{n-1}-u_{n-2}$: $u_0=1$ and $u_1=2$ in WolframAlpha

How can I plot

Plotting the sequence

$$u_n = 2u_{n-1}-u_{n-2}.$$

with starting values $u_0=1$ and $u_1=2$ in Wolframalpha ? Or any graphing calculator.

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Out of curiosity, why do you want to plot it? –  Daniel Fischer Nov 8 '13 at 1:32
@DanielFischer visualisation –  user106280 Nov 8 '13 at 1:37
Aha. I don't know how to make Wolfram Alpha plot it, but I can tell you that $u_n = n+1$, so you can visualise that even without plot. –  Daniel Fischer Nov 8 '13 at 1:39
@DanielFischer But how did you get there? Do you know how to put it on any graphing calculator? –  user106280 Nov 8 '13 at 1:57
Do you mean $u_n = 2u_{n-1} + u_{n-2}?$ –  Omnomnomnom Nov 8 '13 at 2:19

Recursive definitions like this can be resolved fairly easily using either generating functions or the $Z$-transform.