$S/N$

c

$E\left[N\right]$

1

0

9.000000

2

5

8.266860

3

10

6.624890

4

15

4.941387

5

20

3.525723

6

25

2.440853

7

30

1.653255

8

35

1.101388

9

40

0.724263

10

45

0.471310