3 problems

Rational conjugacy growth conjecture. The spherical conjugacy growth series of $G$ is rational only if $G$ is virtually abelian.

Let $R$ be a commutative domain with quotient field $K$, let $X$ be an alphabet, and let $S\in R\langle\!\langle X\rangle\!\rangle$ be a noncommutative formal power series. The ser…

Let $A(t)$ be the generating series whose first ten coefficients are … Rationality conjecture. The series is … This illustrates how Padé approximants can suggest rationality from f…