an episode of a TV series

[color=indigo]1-I remember an episode of a TV series I watched.
[color=red]2-I remember the episode of a TV series I watched.

Can one use this sentence if I only watched that single episode?

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Is this sentence correct:

[color=darkblue]3-I remember an episode I watched of a TV series.

Gratefully,
Navi.

2 - you would probably have to say ‘I remember the episode of the TV series…’

  1. is not as grammatically correct.

It’s a clumsy sentence in all cases.