We consider a large class of sequences, called admissible sequences, which are defined by systems of (possibly nonlinear) difference equations. A procedure for recursively enumerating the algebraic dependencies of such sequences is presented. Also a procedure for solving linear difference equations with admissible sequences as coefficients is proposed. The methods are illustrated on some problems arising in the literature on special functions and combinatorial sequences. Key words: Difference Equations, Algebraic Dependencies, Symbolic Summation,