human
What is a code to number of Permutations such that no Three Terms forms Increasing Subsequence and the other steps required given the following:
Number of Permutations such that no Three Terms forms Increasing Subsequence | Returns value of Binomial Coefficient C ( n , k ).
Since C ( n , k ) = C ( n , n - k ).
Calculate value of [ n * ( n - 1 ) * -- - * ( n - k + 1 ) ] [ k * ( k - 1 ) * -- - * 1 ].
A Binomial coefficient based function to find nth catalan number in O ( n ) time.
Calculate value of 2 nCn.
return 2 nCn / ( n + 1 ).
Driver code"
How can the above be solved in Python?
assistant
#Here is code to number of Permutations such that no Three Terms forms Increasing Subsequence and the other steps required.
 def binomialCoeff ( n , k ) :
	res = 1
	if k > n - k :
		k = n - k
	for i in range ( k ) :
		res = res * ( n - i )
		res = res // ( i + 1 )
	return res
def catalan ( n ) :
	c = binomialCoeff ( 2 * n , n )
	return c // ( n + 1 )
n = 3
print ( catalan ( n ) )