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Edwill
Posts:
1
Registered:
1/29/05


arithmetic progression that's also a geometric one, with a known largest number, need advice
Posted:
Jan 25, 2005 6:00 PM


Hi all,
The problem is that an arithmetic progression (a_1,...,a_n), is also a geometric progression (after applying some permutation). They (a_i's) are all different, and the largest number of them is 2004.
Any idea to begin with to make a breakthrough?
So far,
1). they have the same sum 2). the series is either monotonic increasing, or decreasing 3). if 2). is the case, and without loss of generality, can i assume a_n=2004. or am i already lost in 2).?
Thank you very much...I just need some enlightening hint...:D



