If each set of four were to be repeated, it'd be impossible, because after 0000 or 1111 the next digit must be either 0 or 1, which will be a repeat of 0000, 1111, 0001 or 1110. So, the question would only be valid for a condensed string that happens to includes all combinations but not more than once. (This is probably what you are asking, but i did not see it so clearly at first.)

In reply to Re: (OT) A different kind of 'combinatorics' by chacham
in thread (OT) A different kind of 'combinatorics' by BrowserUk

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