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3 votes
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Regarding the Challenge Problem in 3Blue1Brown's most recent video: Will $\binom{x}{4}+\binom{x}{2}+1=2^k$ for $x>10$? [duplicate]

Link to the video here with timestamp In deriving the formula for regions of Moser's Circle Problem, it observed that the formula $$ F(x)=\binom{x}{4}+\binom{x}{2}+1 $$ achieves values that are equal ...
wjmccann's user avatar
  • 315
11 votes
1 answer
774 views

2-adic Logarithm and Resistance of n-dimensional Cube

Resistance across opposite vertices of n-dimensional cube with each edge at one ohm resistance is $$R_n=\sum_{k=0}^{n-1}\frac1{(n-k){n\choose k}}=\frac1n\sum_{k=0}^{n-1}\frac1{{n-1\choose k}}.$$ The ...
Alexey Ustinov's user avatar