Lax pair, auto-Bäcklund transformation and conservation law for a generalized variable-coefficient KdV equation with external-force term

A generalized variable-coefficient KdV equation with perturbed and external-force terms is investigated in this Letter. Lax pair, Riccati-type auto-Bäcklund transformation and Wahlquist–Estabrook-type auto-Bäcklund transformation (WE–BT) are constructed. Based on the WE–BT, the nonlinear superposition formula is obtained and an infinite number of conservation laws are derived recursively, then the analytic solutions are provided including periodic, one-soliton-like and two-soliton-like solutions with inhomogeneous coefficients, external-force term and eigenvalue.