You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl-[(3-butylcyclopropen-1-yl)methylidene]-propylazanium ?
user
C21H34N+
assistant