Next number in sequence patter 7, 21, 8, 72, 9

The next number would be 243.

3 x 7 = 21

9 x 8 = 72

_ x 9 = __

In this pattern, the second number seems to be consecutive integers. The first number seems to be multiples of 3. 3^1 is 3, and 3^2 is 9, so the next number would have to be 3^3 times 9. This would be 27 x 9 = 243.