RosettaCodeData/Task/Catalan-numbers-Pascals-triangle/Python/catalan-numbers-pascals-triangle-2.py
2015-02-20 09:02:09 -05:00

9 lines
256 B
Python

def catalan_number(n):
nm = dm = 1
for k in range(2, n+1):
nm, dm = ( nm*(n+k), dm*k )
return nm/dm
print [catalan_number(n) for n in range(1, 16)]
[1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900, 2674440, 9694845]