0 , 1 , 9 , 36 , 99 , 225 , 441

From above given series , we can see that
The differences are given as -
Second term - First term = 1? 0 = 1 = 1³;
Third term - Second term = 9 ? 1= 8 = 2³;
Similarly , we can find all others terms also.
Fourth term - Third term = 36 ? 9 = 27 = 3³;
Fifth term - Fourth term = 99 ? 36 = 63 ? 4 ³
But , Fifth term - Fourth term = 100 ? 36 = 64 = 4³;
Here , fifth term 99 is wrong , it should be 100 as fifth term .
Sixth term - Fifth term = 225 ? 100 = 125 = 5³;
Seventh term - Sixth term = 441? 225 = 216 = 6³