def factorial(s):

    i=1

    prod=1

    if s<=1:

        return 1

    else:

        while i <= s:

            prod=prod*i

            i=i+1

        return prod

def triangles():

    n=1

    while True:

        yield [factorial(n-1)//(factorial(m-1)*factorial(n-m))  for m in list(range(n+1))[1:]]

        n=n+1

    return 'done'