Merge pull request rathoresrikant#757 from osoba/catalan-python

added catalan number algorithm in python without using the factorial function

Algorithms/Mathematical Algorithms/catalan_without_factorial.py

@@ -0,0 +1,17 @@
+'''Python program to find the nth catalan number without using the computationally intensive factorial function'''
+
+number = int(input('Enter a number: '))
+
+
+
+def catalan(n):
+    if n <= 1: return 1
+
+    numerator, denominator = 1, 1
+
+    for i in range(2, n+1):
+      numerator *= (n+i)
+      denominator *= i
+    return int(numerator/denominator)
+
+print( catalan(number) )