I consider an elliptic curve $\mathcal C$ over $\mathbb{C}$ and the multiplication by $[n]$ map on the curve. Then I consider an indecomposable vector bundle $E$ on $C$. What can I say of the pullback $[n]^{*}E$? It is still indecomposable? If I know $E$ from the Atiyah's classification, may I say something more on $[n]^{*}E$?
Thank you in advance.