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Old Mar27-09, 05:59 PM                  #1
boy_travels

boy_travels is Offline:
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Integer tuples with equal L1 and L2 norms

Let x and y be n-tuples of non-negative integers.

Furthermore,

sum x_i = sum y_i

and,

sum x_i^2 = sum y_i^2

Is it true that x must be a permutation of y?

Cheers!
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Old Mar27-09, 06:50 PM                  #2
boy_travels

boy_travels is Offline:
Posts: 2
Re: Integer tuples with equal L1 and L2 norms

Sorry. I found a way to generate trivial counterexamples.

E.g. x = [16 13 9 4]
y = [17 12 8 5]

etc.
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