divide 1 to 20.py

def primal(n):
        factors = []
        d = 2

        while n > 1:
                while n % d == 0:
                        factors.append(d)
                        n = n / d
                d += 1

        return factors

if __name__ == '__main__':
        factors = {}

        i = 0
        while i <= 20:
                tmp_factors = {}

                for f in primal(i):
                        tmp_factors[f] = tmp_factors.get(f, 0) + 1

                for f in tmp_factors:
                        count = tmp_factors[f]

                        if count > factors.get(f, 0):
                                factors[f] = count

                i += 1

        print(factors)

        total = 1

        for f in factors:
                count = factors[f]

                total *= f**count

        print total