T(n,偶数k)=(k-n)*T(n-1,k-1);
T(n,奇数k)=(k-n+1)*T(n-1,k-1)+2*总和(对于i=n..k-2,T(n-1,i));
T(n,2*n-1)=2*(n-1)!;
T(n,2*n-2)=2*(n-1)-2*(n-2)!当n>2时;
T(n,2*n-3)=4*(n-1)-12*(n-2)+4*(n-3)!当n>3时;
T(n,2*n-4)=4*(n-1)-24*(n-2)+28*(n-3)-4*(n-4)!当n>4时;
T(n,2*n-5)=6*(n-1)-60*(n-2)+152*(n-3)-96*(n-4)+8*(n-5)!对于n>5。
(结束)
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