You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 5-ethyl-9-(4-nitrophenyl)-13,15-dioxa-4,7,8-triazatetracyclo[8.7.0.03,7.012,16]heptadeca-1(17),3,5,8,10,12(16)-hexaene into its molecular formula.
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C20H16N4O4
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