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Pruthviraj
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Are there only two solutions for $1+3+9+...+3^m=2^n$

Are there only two solutions for $$\sum_{k=0}^m3^k=2^n$$

Such as $3^0=2^0$ and $3^0+3^1=2^2$

Note

• If $m$ is even then $\sum_{k=0}^m3^k$ will be odd.

$$\sum_{k=0}^m3^k=\sum_{k=0}^m\binom{m+1}{k+1}2^k=\sum_{k=0}^{m}\sum_{l=0}^{k}\binom{m+1}{k+1}\binom{k}{l}$$

Pruthviraj
  • 599
  • 3
  • 13