. (a) For each n > 0 let 7 17x An = [x] 1 4x 5x2 Use partial fractions to find an explicit formula for an in terms of n for all n > 0. (b) Could {an}n>o be the sequence of coefficients of the generating series for a set S of binary strings (where the weight of each string is its length)? Justify your answer. . (a) For each n > 0 let 7 17x An = [x] 1 4x 5x2 Use partial fractions to find an explicit formula for an in terms of n for all n > 0. (b) Could {an}n>o be the sequence of coefficients of the generating series for a set S of binary strings (where the weight of each string is its length)? Justify your