from math import factorial
import functools


def memoize(func):
    cache = {}

    def memoized(key):
        # Returned, new, memoized version of decorated function
        if key not in cache:
            cache[key] = func(key)
        return cache[key]
    return functools.update_wrapper(memoized, func)


@memoize
def fact(n):
    return factorial(n)


def cat_direct(n):
    return fact(2 * n) // fact(n + 1) // fact(n)


@memoize
def catR1(n):
    return 1 if n == 0 else (
        sum(catR1(i) * catR1(n - 1 - i) for i in range(n))
    )


@memoize
def catR2(n):
    return 1 if n == 0 else (
        ((4 * n - 2) * catR2(n - 1)) // (n + 1)
    )


if __name__ == '__main__':
    def pr(results):
        fmt = '%-10s %-10s %-10s'
        print((fmt % tuple(c.__name__ for c in defs)).upper())
        print(fmt % (('=' * 10,) * 3))
        for r in zip(*results):
            print(fmt % r)

    defs = (cat_direct, catR1, catR2)
    results = [tuple(c(i) for i in range(15)) for c in defs]
    pr(results)