Three Memorial Cents with identical mechanical tripling

I have three 1960-D cents with the exact same mechanical tripling. Is this unusual? On the reverse the word States has tripling.

 

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Here is a close up.

 

I looked, cleaned my glasses and still don't see strike doubling, aka machine or mechanical doubling.

 

Thanks Sal. Here are some better pictures.

 

I'm assuming, normal for this to happen. Awaiting more answers.....