2nd term = (1st term) x 1 + 1 = 15 x 1 + 1 = 16. 3rd term = (2nd term) x 2 + 2 = 16 x 2 + 2 = 34. 4th term = (3th term) x 3 + 3 = 34 x 3 + 3 = 105. 5th term = (4th term) x 4 + 4 = 105 x 4 + 4 = 424 6th term = (5th term) x 5 + 5 = 424 x 5 + 5 = 2125 6th term should 2125 instead of 2124.