We fly from Hong Kong - Shanghai and one day later to Amsterdam. Eligble for 72hours free tansit?

We don't know for sure if we need to apply for a single entry or a double entry permit (we are staying in China for 2,5 weeks). Then travel to Hong Kong for a few days - back to Shanghai and the next day flying home to Amsterdam.

I think we are eligble for the 72hours free transit the second time right? Then I only need to apply for the single entry visa?