$y(2) = 2y(2-1)-y(2-2)=2y(1)-y(0) = 2 \\cdot 1 - 0 = 2$
\n$y(3) = 2y(3-1)-y_(3-2)=2y(2)-y(1) = 2 \\cdot 2 - 1 = 3$
\n$y(4) = 2y(4-1)-y(4-2)=2y(3)-y(2) = 2 \\cdot 3 - 2 = 4$
\nSo, it looks like $y_5=5, y_6=6,...$ and $y_n=n$.
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\n$y_2 = 2y_{2-1}-y_{2-2}=2y_1-y_0 = 2 \\cdot 1 - 0 = 2$
\n$y_3 = 2y_{3-1}-y_{3-2}=2y_2-y_1 = ...$
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