N    FACT(N)      STIR(N)      Accuracy (%)
1    1            0.92213      7.78629     
2    2            1.919        4.04977     
3    6            5.8362       2.72983     
4    24           23.50617     2.0576      
5    120          118.01918    1.65067     
6    720          710.07824    1.37802     
7    5040         4980.39453   1.18264     
8    40320        39902.39843  1.03571     
9    362880       359537       0.92124     
10   3628800      3598696.75   0.82956     
11   3.99168E7    3.96156E7    0.75447     
12   4.79001E8    4.75687E8    0.69184     
13   6.22702E9    6.18723E9    0.63888     
14   8.71782E10   8.66611E10   0.59322     
15   1.30767E12   1.30043E12   0.55379     
16   2.09227E13   2.08141E13   0.51938     
17   3.55687E14   3.53948E14   0.48891     
18   6.40237E15   6.3728E15    0.46187     
19   1.21645E17   1.21112E17   0.43767     
20   2.4329E18    2.42278E18   0.41568