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I'm trying to solve this little problem. So far no luck. Could anyone help? Thanks in advance :)

What is the ten digit number such that the i-th digit is the number of i's in the number ( 0<= i <= 9) (the 0th position is number of zeros in the number, the 1st position is number of ones in the number,…)?

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Here is one solution: $$6210001000$$ $$(0123456789)$$

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  • $\begingroup$ I think the problem wants it the other way around. $\endgroup$ – Listing May 17 '11 at 18:03
  • $\begingroup$ It looks like the request was in the opposite order, 6210001000, which avoids leading zeros. $\endgroup$ – Ross Millikan May 17 '11 at 18:04
  • $\begingroup$ Sloan (oeis.org/A108551) claims this solution is unique. Is there an easy way to see this? $\endgroup$ – Nate Eldredge May 17 '11 at 19:08
  • $\begingroup$ A more general version of this question came up recently. Put 6210001000 in the search box to see it. $\endgroup$ – Robert Soupe Jun 28 '14 at 16:30

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