You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[2-(2,7-dimethyl-1H-indol-3-yl)ethyl]pyrazolo[1,5-a]pyridine-2-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C20H20N4O
assistant