$\Vert e^n\left(h,\tau \right)\Vert /\Vert e^{2n}\left(\frac{h}{2},\frac{\tau }{2}\right)\Vert$

${\Vert e^n\left(h,\tau \right)\Vert }_{\infty }/{\Vert e^{2n}\left(\frac{h}{2},\frac{\tau }{2}\right)\Vert }_{\infty }$

$\tau =h=0.1$

$\tau =h=0.05$

$\tau =h=0.025$

$\tau =h=0.1$

$\tau =h=0.05$

$\tau =h=0.025$

$t=5$

—

3.98780

4.00238

—

3.97074

3.98004

$t=10$

—

4.00729

4.02075

—

3.99053

3.99874

$t=15$

—

4.02057

4.03670

—

4.00271

4.01321

$t=20$

—

4.03291

4.05267

—

4.01381

4.02767