Catalan
(Built-in Mathematica Symbol) Catalan is Catalan's constant, with numerical value \[TildeEqual] 0.915966.
CatalanNumber[n] gives the n\[Null]^th Catalan number C_n.
Denominator[expr] gives the denominator of expr.
DistributionParameterAssumptions[dist] gives a logical expression for assumptions on parameters in the symbolic distribution dist.
DistributionParameterQ[dist] yields True if dist is a valid distribution, and yields False otherwise.
Divisors[n] gives a list of the integers that divide n.
FindGraphIsomorphism[g_1, g_2] finds an isomorphism that maps the graph g_1 to g_2 by renaming vertices.
FortranForm[expr] prints as a Fortran language version of expr.
GoldenRatio is the golden ratio \[Phi] = 1/2 (Sqrt[5] + 1), with numerical value \[TildeEqual] 1.61803.
GraphCenter[g] gives the set of vertices with minimum eccentricity in the graph g.