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,…)?
Here is one solution: $$6210001000$$ $$(0123456789)$$