n−3 | n−5 | |||
(n−2)!*(n−4)!*(n−6)!*...*5!*3!*(( | )!)−1*(( | )!)−1* | ||
2 | 2 |
n−7 | ||
*(( | )!)−1*...*(3!)−1*(2!)−1*(n−3)n−12* | |
2 |
n−3 | n−5 | n−7 | ||||
(( | )!)−1*(( | )!)−1*(( | )!)−1*...*(3!)−1*(2!)−1 ? | |||
2 | 2 | 2 |
1 | 1 | 1 | ||||
(( | (n−3))!)−1*(( | (n−5))!)−1*(( | (n−7))!)−1*...*(3!)−1*(2!)−1= | |||
2 | 2 | 2 |
1 | 1 | 1 | ||||
=( | (n−3))−1*( | (n−5))−2*( | (n−7))−3*...*3−7*2−8= | |||
2 | 2 | 2 |
1 | ||
=∏k=0n−72 ( | (n−(2k+3)))−(k+1) | |
2 |