threezeros.2.py

class BaseSevenNumber:

    def __init__(self):
        self.digits = [1]

    def Double(self):
        for i in range(0, len(self.digits)):
            self.digits[i] = self.digits[i] * 2
        for i in range(len(self.digits) - 1, -1, -1):
            if self.digits[i] > 6:
                self.digits[i] = self.digits[i] - 7
                if i == 0: self.digits.insert(0,1)
                else: self.digits[i - 1] = self.digits[i - 1] + 1

    def HasThreeZeros(self):
        for i in range(0, len(self.digits) - 2):
            if self.digits[i] == 0 and self.digits[i + 1] == 0 and self.digits[i + 2] == 0:
                return True
        return False

def SolveRiddle(maxFailuresAssumeFound):
    bsn = BaseSevenNumber()
    failures = 0
    power = 1
    while failures < maxFailuresAssumeFound:
        bsn.Double()
        if bsn.HasThreeZeros(): failures = failures + 1
        else:
            failures = 0
            print power
        power = power + 1

SolveRiddle(10000)