History of Growth rates of hyperbolic Coxeter simplex groups

     finite-volume non-cocompact tetrahedral groups, which this table does not hold,     have growth rates that are Perron and often Pisot rather than Salem: $[6,3,6]$-    gives the golden ratio, a root of $t^2-t-1$, and $[4,3,6]$ the plastic number,-    a root of $t^3-t^2-1$.'+    gives HREF{Golden_ratio}[the golden ratio], a root of $t^2-t-1$, and $[4,3,6]$+    the plastic number, a root of $t^3-t^2-1$.' Formulas:   formula-steinberg: For $W(t)=\sum_{k\geq0}a_k t^k$, Steinberg's formula CITE{Steinberg}