If the first n terms of the equal ratio sequence and Sn = 2 (13) n + K, then the value of the constant k is______ .

If the first n terms of the equal ratio sequence and Sn = 2 (13) n + K, then the value of the constant k is______ .

∵ A1 = 2 × 13 + k = 23 + K, A2 = S2 − S1 = (2 × 19 + k) − (2 × 13 + k) = − 49, A3 = s3-s2 = (2 × 127 + k) & nbsp; − (2 × 19 + k) & nbsp; = − 427, ∵ (− 49) 2 = (− 427) & nbsp; × (23 + k), ∵ k = - 2