GroupOrder[group] returns the number of elements of group.
Hyperfactorial[n] gives the hyperfactorial function H(n).
LeviCivitaTensor[d] gives the d-dimensional Levi-Civita totally antisymmetric tensor.
MangoldtLambda[n] gives the von Mangoldt function \[CapitalLambda](n).
Manual
(Built-in Mathematica Symbol) Manual represents an option or other value that is to be selected manually, usually by some form of interactive manipulation.
MorletWavelet[] represents a Morlet wavelet.
RealBlockDiagonalForm is an option for SchurDecomposition and related functions which specifies whether 2*2 blocks of real values should be used on matrix diagonals in place ...
RiemannR[x] gives the Riemann prime counting function R(x).
RulerUnits is an option for notebooks that specifies the units in the ruler toolbar.
StartScheduledTask[obj] starts the task represented by obj.