The sequence follows the rule : "Add Three"
So if the first number is 0.
0 + 3 = 3 ( 1 * 3 )
3 + 3 = 6 ( 2 * 3 )
6 + 3 = 9 ( 3 * 3 )
9 + 3 = 12 ( 4 * 3 )
12 + 3 = 15 ( 5 * 3 )
15 + 3 = 18 ( 6 * 3 )
Notice how all these numbers are multiples of 3.
This can either be solved through addition or multiplication.
The six terms of the numerical pattern are:
3, 6, 9, 12, 15, and 18.
Cheers,
ROR