I think the wording of the question could do with clarification. Do you start with the penny and it is doubled on day one or start with zero and get a penny on the first day?
I repeated 4 times in the video: You "RECEIVE".... then ...."Keeps doubling every Day for the NEXT 30 days" which means the day you "Receive" is NOT included in the calculation. If doubling starts the day you RECEIVE the penny that means doubling only 29 times.