Is This the Correct Identity for Natural Numbers?

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oszust001
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How can I show that:
[tex]\sum_{i=0}^{n}2^{n-i} {n+i \choose i}=2^{2^{n}}[/tex]
for every natural numbers
 
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The identity is wrong, it should be

[tex] \sum_{i=0}^{n}2^{n-i} {n+i \choose i}=2^{2 n} [/tex]
 
ok my foult. so how can i solve that equation?
 
Well, this
[tex] \sum_{i=0}^{n}2^{n-i} {n+i \choose i}=2^{2 n} [/tex]

is an identity it is true for all [tex]n[/tex] but, if I understand correctly, you may ask for the values of [tex]n[/tex] that make
[tex] \sum_{i=0}^{n}2^{n-i} {n+i \choose i}=2^{2^{n}} [/tex]
true. In this case we have the equation [tex]2n=2^{2^{n}}[/tex], and the solutions are [tex]n \in \lbrace 1,2 \rbrace[/tex].
 
AtomSeven said:
The identity is wrong, it should be

[tex] \sum_{i=0}^{n}2^{n-i} {n+i \choose i}=2^{2 n} [/tex]
Version of AtomSeven is good.
How can I show that [tex] \sum_{i=0}^{n}2^{n-i} {n+i \choose i}=2^{2 n} [/tex]
is good for every natural numbers