7=729x3=2187
8＝2187x3＝6561
9＝6561x3＝19683
10＝19683x3＝59049
6to7＝486x3＝1458
7to8＝1458x3＝4374
8to9＝4374x3＝13122
9to10＝13122x3＝39366
