pade(nd, dd, s) computes the quotient of polynomials (if it exists) with numerator degree at most nd and denominator degree at most dd which matches the series s to order nd + dd.
pade(nd, dd, ns, ds) computes the approximant as a quotient of polynomials (if it exists) for arguments nd (numerator degree of approximant), dd (denominator degree of approximant), ns (numerator series of function), and ds (denominator series of function).