The given series is 2,3, 8, 28, 112, 565 The next term of the series is given by following pattern 3 = 2 * 1 + 1 8 = 3 * 2 + 2 27 = 8 * 3 + 3 112 = 27 * 4 + 4 565 = 112 * 5 + 5 thus 4th term is wrong , instead of 28 , it should be 27.