抄録
The explicit Runge-Kutta method is one of the numerical solutions of the initial value problem of an ordinary differential equation. This method is proposed up to the 10th formula. E.Hairer showed the 17 stage 10th order formula. It is shown that the method is extended and 25 stage the 12th order formula can be determined. It is shown using a numerical example that the formulas is 12th order. And it was also shown that high precision calculation can do the formula efficiently.
