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54 votes
2 answers
8k views

Walsh Fourier transform of the Möbius function

This question is related to this previous question where I asked about ordinary Fourier coefficients. Special case: is Möbius nearly orthogonal to Morse August Ferdinand Möbius (November 17, 1790 – ...
6 votes
2 answers
385 views

Is the nth-power-sum graph connected?

This post was inspired by the Square-Sum Problem presented in Numberphile by Matt Parker. He asked about Hamiltonianness for $n=2$, and we ask about connectedness for all $n \in \mathbb{N}^*$. ...
10 votes
3 answers
1k views

Explicit formula for elementary symmetric sum

For $k\ge1$, $j\ge1$, Let $$e_k(j)=\sum_{1\le i_1<...<i_k\le j}i_1\cdot\cdot\cdot i_k.$$ We know that $e_k(j)$ is a polynomial in $j$ with coefficients depending on $k$. I am curious about ...