prove-that-n-1-n-4-n-7-1-3-2-n-2cos-n-2-pi-3-

Question Number 121339 by Eric002 last updated on 06/Nov/20

p r o v e t h a t

(\begin{matrix} n \\ 1 \end{matrix}) + (\begin{matrix} n \\ 4 \end{matrix}) + (\begin{matrix} n \\ 7 \end{matrix}) + \dots . = \frac{1}{3} (2^{n} + 2 c o s \frac{(n - 2) π}{3})

Answered by mindispower last updated on 06/Nov/20

w h s t i s

t h e l o g i q u e

\sum_{k} (\begin{matrix} n \\ g (k) \end{matrix}), w h a t i s g (k)

Commented by Eric002 last updated on 06/Nov/20

t h e r e w a s a t y p o i c o r r e c t e d i t

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