I've got a differential equation : (x^2)y'' +(1+3x)y' +y=0 and have used frobenius method to turn it into a power series. that bit was fine, have

y=((n-1)(n-2)+3(n-1)+1)An-1 + nAn =0

problem is the question then says to find two linearly independent solutions, but i can only make it work to get one solution. because i have An and An-1 there is only 1 between them and for two solutions would been it to be something like An and An-2. Any suggestions??

Sarah