fgamma(1)=0.999999989064903 	 sgamma(1)=1.00000000012234 0!=1
fgamma(2)=0.999999989064903 	 sgamma(2)=1.00000000012234 1!=1
fgamma(3)=1.99999997812981 	 sgamma(3)=2.00000000024468 2!=2
fgamma(4)=5.99999993438942 	 sgamma(4)=6.00000000073404 3!=6
fgamma(5)=23.9999997375577 	 sgamma(5)=24.0000000029362 4!=24
fgamma(6)=119.999998687788 	 sgamma(6)=120.000000014681 5!=120
fgamma(7)=719.99999212673 	 sgamma(7)=720.000000088085 6!=720
fgamma(8)=5039.99994488711 	 sgamma(8)=5040.00000061659 7!=5040
fgamma(9)=40319.9995590969 	 sgamma(9)=40320.0000049328 8!=40320
sqrt(-1)=(0, 1)