[EStyled TextBold [EIdentifier "C"],EDelimited "(" ")" [Right (EIdentifier "n"),Right (ESymbol Pun ","),Right (EIdentifier "k")],ESymbol Rel "=",ESubsup (EStyled TextBold [EIdentifier "C"]) (EIdentifier "k") (EIdentifier "n"),ESymbol Rel "=",ESub (EGrouped []) (EIdentifier "n"),ESub (EStyled TextBold [EIdentifier "C"]) (EIdentifier "k"),ESymbol Rel "=",EDelimited "(" ")" [Right (EFraction NoLineFrac (EIdentifier "n") (EIdentifier "k"))],ESymbol Rel "=",EFraction NormalFrac (EGrouped [EIdentifier "n",ESymbol Ord "!"]) (EGrouped [EIdentifier "k",ESymbol Ord "!",ESpace (1 % 6),EDelimited "(" ")" [Right (EIdentifier "n"),Right (ESymbol Bin "\8722"),Right (EIdentifier "k")],ESymbol Ord "!"])]