how about 3,211,000
That would be it.
While it's obvious on inspection that this score fits the description, proving that it is the only possible answer is slightly more complicated. As a matter of fact I'll take one of the standard textbook copouts and say it is beyond the scope of this post. Suffice it to say for numbers of digits less than 10, here are the only numbers that fit:
n=1: no sequence possible
n=2: no sequence possible
n=3: no sequence possible
n=4: 1210, 2020
n=5: 21200
n=6: no sequence possible
n=7: 3211000
n=8: 42101000
n=9: 521001000
n=10: 6210001000
The question stated that the score rolls over at 10 million, so we know it wasn't 42,101,000; 521,001,000; or 6,210,001,000.
Why couldn't it have been 21,200 (or even 2020)? Those scores are not possible as any sum of multiples of 1300, 2300, and 7900. For analysis along these lines you may check this page on
Frobenius Numbers. This also related to my question regarding Zantar II several years ago on the
TG forum.
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