i am having a problem printing using a single loop

Question

input output
n=1 1
n=2 1 4
n=3 1 4 7
n=4 1 4 7 10

Answer 1

row is string

Answer 2

whats the logic

Answer 3

Sumit,
I think it means 1 + <i> * 3
Where <i> is a loop counter initialized by zero, run the loop while <i> < <N> ...