3n, let n = 0, 1, 2, 3, 4, 5,....
When n= 0, 3n = 3*0 = 0
When n= 1, 3n = 3*1= 3
When n= 2, 3n = 3*2 = 6
When n= 3, 3n = 3*3 = 9
When n= 4, 3n = 3*4 = 12
When n= 5, 3n = 3*5 = 15
...
Sequence 3n = 0, 3, 6, 9, 12, 15, ..... for n = 0, 1, 2, 3, 4, 5,.....