Find the solution of $x^2y'' + 5xy' + (4 + 4 x)y = 0, \,x > 0$ of the form $$y_1 = x^r\sum_{n = 0}^{\infty} c_n x^n,$$ where $c_0 = 1$. Enter

$r =$
$c_n =$ , $\,n = 1, 2, 3, \ldots$