Consider Erase the right 90
Find a sequence of the numbers from 1 to 100, not necessarily in that order, such that exactly ten groups of 10 form exactly ten distinct subsequences, which need not be continuous, in each of strictly increasing and strictly decreasing order.
List the 20 subsequences.
(In reply to
This should work by Jer)
This is the sort of thing I was also thinking of, but I thought it didn't match what was asked for: exactly ten distinct sequences. Are we to assume that subsequences that are not specified do not exist? They are there, even if not set aside as such: such as 10, 19, 35, 42,...,100.

Posted by Charlie
on 20160214 11:33:18 