MathOverflow

Let
$$X_{10}\subset \mathbb P(1,2,3,5)$$
be a quasi-smooth hypersurface of degree $10$ with a unique $A_2$ (du Val) singularity at $[0:0:1:0]$.Let $\pi:\mathcal X_{10}\to X_{10}$ be the canonical smooth Deligne--Mumford stack (the canonical stack of $X_{10}$).Over the singular point the stabilizer...

I'm studying a syntactic swap operation and was led to a construction I'd like to identify in the literature.
Setup:
Let T be an equational theory with binary operations + and ×. Define ι (swap) as: exchange + and × while preserving parse structure.

On the fast-growing integer sequence TCF(n)
I recently came across a sequence of integers called TCF(n), introduced by the YouTuber @8.25Creator roughly 3 months ago. There is very little public information about it, and I am curious about its mathematical structure and growth behavior....

I am using the polynomial asymptotic expansion for iterated harmonic sums described in Polynomial asymptotics for iterated harmonic sums (answer by Carlo Beenakker). Let\begin{equation}H_{n,k}:=\sum_{\substack{m_1\cdots m_k\le n\\ m_i\ge 2}}\frac{1}...