Dot
(Built-in Mathematica Symbol) a.b.c or Dot[a, b, c] gives products of vectors, matrices, and tensors.
Factor
(Built-in Mathematica Symbol) Factor[poly] factors a polynomial over the integers. Factor[poly, Modulus -> p] factors a polynomial modulo a prime p. Factor[poly, Extension -> {a_1, a_2, ...}] factors a ...
FisherHypergeometricDistribution[n, n_succ, n_tot, w] represents a Fisher noncentral hypergeometric distribution.
FisherZDistribution[n, m] represents a Fisher z distribution with n numerator and m denominator degrees of freedom.
IntegerPartitions[n] gives a list of all possible ways to partition the integer n into smaller integers. IntegerPartitions[n, k] gives partitions into at most k integers. ...
NProduct[f, {i, i_min, i_max}] gives a numerical approximation to the product \[Product]i = i_min i_max f.NProduct[f, {i, i_min, i_max, di}] uses a step di in the product.
NumberForm[expr, n] prints with approximate real numbers in expr given to n-digit precision.
PolyGamma[z] gives the digamma function \[Psi](z). PolyGamma[n, z] gives the n\[Null]^th derivative of the digamma function \[Psi] (n) (z).
RootApproximant[x] converts the number x to one of the "simplest" algebraic numbers that approximates it well.RootApproximant[x, n] finds an algebraic number of degree at ...
Sech
(Built-in Mathematica Symbol) Sech[z] gives the hyperbolic secant of z.