- #1

Punkyc7

- 420

- 0

a[itex]_{n}[/itex]= 6 * a[itex]_{n-1}[/itex]+ a[itex]_{n-2}[/itex] a[itex]_{0}[/itex]=2, a[itex]_{1}[/itex]=1

So here is what I did

I said let A = [itex]\sum[/itex][itex]_{2>=n} [/itex]a[itex]_{n}[/itex]x[itex]^{n}[/itex]

then I got

A = 6x (A+x) + x[itex]^{2}[/itex](A +x+2)

which gets me

A= [itex]\frac{6x^2+x^{3} +2x}{1-6x - x^2}[/itex]

ButI should get [itex]\frac{2-x}{1-6x - x^2}[/itex]

Can any one tell me what I am doing wrong ?