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oszust001
#5
Jan12-11, 11:17 AM
P: 10
Quote Quote by AtomSeven View Post
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