BesselY (Built-in Mathematica Symbol)

BesselY[n, z] gives the Bessel function of the second kind Y_n (z).

Catalan (Built-in Mathematica Symbol)

Catalan is Catalan's constant, with numerical value \[TildeEqual] 0.915966.

CatalanNumber (Built-in Mathematica Symbol)

CatalanNumber[n] gives the n\[Null]^th Catalan number C_n.

ChebyshevT (Built-in Mathematica Symbol)

ChebyshevT[n, x] gives the Chebyshev polynomial of the first kind T_n (x).

DedekindEta (Built-in Mathematica Symbol)

DedekindEta[\[Tau]] gives the Dedekind eta modular elliptic function \[Eta](\[Tau]).

DiscreteDelta (Built-in Mathematica Symbol)

DiscreteDelta[n_1, n_2, ...] gives the discrete delta function \[Delta] (n_1, n_2, ...), equal to 1 if all the n_i are zero, and 0 otherwise.

EllipticNomeQ (Built-in Mathematica Symbol)

EllipticNomeQ[m] gives the nome q corresponding to the parameter m in an elliptic function.

Equivalent (Built-in Mathematica Symbol)

Equivalent[e_1, e_2, ...] represents the logical equivalence e_1 \[DoubleLeftRightArrow] e_2 \[DoubleLeftRightArrow] ..., giving True when all of the e_i are the same.

EulerGamma (Built-in Mathematica Symbol)

EulerGamma is Euler's constant \[Gamma], with numerical value \[TildeEqual] 0.577216.

GoldenRatio (Built-in Mathematica Symbol)

GoldenRatio is the golden ratio \[Phi] = 1/2 (Sqrt[5] + 1), with numerical value \[TildeEqual] 1.61803.