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Mathematical identity involving sums of binomial coefficients
Abel's binomial theorem , named after Niels Henrik Abel , is a mathematical identity involving sums of binomial coefficients . It states the following:
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{\displaystyle \sum _{k=0}^{m}{\binom {m}{k}}(w+m-k)^{m-k-1}(z+k)^{k}=w^{-1}(z+w+m)^{m}.}
Example
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{\displaystyle {\begin{aligned}&{}\quad {\binom {2}{0}}(w+2)^{1}(z+0)^{0}+{\binom {2}{1}}(w+1)^{0}(z+1)^{1}+{\binom {2}{2}}(w+0)^{-1}(z+2)^{2}\\&=(w+2)+2(z+1)+{\frac {(z+2)^{2}}{w}}\\&={\frac {(z+w+2)^{2}}{w}}.\end{aligned}}}
See also
References
