import itertools

values = [6, 9, 20]
results = range(50, 55 + 1)

n = 1
while results:
    combinations = itertools.combinations_with_replacement(values, n)
    for x in list(combinations):
        total = sum(x)
        if total in results:
            print(total, x)
            results.remove(total)
    n += 1