Determine Divergence of Ʃ ((n!)^n) /(4^(4n))

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Homework Statement



Ʃ ((n!)^n) /(4^(4n))

Homework Equations



Root test?



The Attempt at a Solution



Can you do ... the root test so then you will get rid of exponents n and you have

(n!)/n^4 then take the limit and you get ∞ so the original sum is divergent?
 
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Jbreezy said:

Homework Statement



Ʃ ((n!)^n) /(4^(4n))

Homework Equations



Root test?



The Attempt at a Solution



Can you do ... the root test so then you will get rid of exponents n and you have

(n!)/n^4 then take the limit and you get ∞ so the original sum is divergent?

Yes, you use the root test. But the nth root of 4^(4n) isn't n^4.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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