You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 5,10,15,20-tetrakis[9-butyl-6-[3,6-di(carbazol-9-yl)carbazol-9-yl]carbazol-3-yl]-21,23-dihydroporphyrin is given. What is its corresponding molecular formula?
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C228H158N20
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