text: calculating u mentioned in the formula
code: static double ucal ( double u , int n ) { if ( n == 0 ) return 1 ; double temp = u ; for ( int i = 1 ; i <= n / 2 ; i ++ ) temp = temp * ( u - i ) ; for ( int i = 1 ; i < n / 2 ; i ++ ) temp = temp * ( u + i ) ; return temp ; }