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Apr 19, 2023 at 16:22 vote accept T. Amdeberhan
Feb 13, 2022 at 16:23 comment added T. Amdeberhan @SamHopkins: I think all determinants/Pfaffians in the paper (you mentioned) involves the Vandermonde determinant, not the "cyclic type" in the question.
Feb 13, 2022 at 16:21 comment added T. Amdeberhan @darijgrinberg: that's a nice "cousin". Note: $\det(x_{\min\{i,j\}})=(-1)^{m-1}x_1(x_1-x_2)\cdots(x_{m-1}-x_m)$.
Feb 13, 2022 at 12:53 answer added LeechLattice timeline score: 6
Feb 13, 2022 at 2:27 history edited T. Amdeberhan CC BY-SA 4.0
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Feb 13, 2022 at 2:26 comment added T. Amdeberhan I'm sorry but there was a typo: $x_n$ should be $x_{2n}$, in the definition on the matrix.
Feb 13, 2022 at 0:33 comment added Sam Hopkins Seems similar to various determinants and Pfaffians considered by Okada in math.kobe-u.ac.jp/publications/rlm18/9.pdf.
Feb 12, 2022 at 23:45 comment added darij grinberg Also, the true "little brother" of this claim is not the Vandermonde determinant, but the known fact that $\det\left(\left(x_{\min\left\{i,j\right\}}\right)_{1\leq i,j\leq m}\right) = x_1 \left(x_1 - x_2\right) \left(x_2 - x_3\right) \cdots \left(x_{m-1}-x_m\right)$ for any $m \geq 1$.
Feb 12, 2022 at 23:35 comment added darij grinberg This is reminiscent of (4.2) in Donald E. Knuth, Overlapping Pfaffians, Electronic Journal of Combinatorics 32 (1996), issue 2.
Feb 12, 2022 at 23:31 comment added darij grinberg Note also that the matrix is antisymmetric, so it is not surprising that its determinant is a square. The question is why its Pfaffian is this nice.
Feb 12, 2022 at 23:31 comment added darij grinberg Apparently, you can remove the "$-x_n$" part and the determinant becomes $x_1^2 \left(x_1-x_2\right)^2 \left(x_2-x_3\right)^2 \cdots \left(x_{2n-1}-x_{2n}\right)^2$. This should generalize the corrected version of your question.
Feb 12, 2022 at 20:33 history asked T. Amdeberhan CC BY-SA 4.0