PauliMatrix (Built-in Mathematica Symbol)

PauliMatrix[k] gives the k\[Null]^th Pauli spin matrix \[Sigma]_k.

PrimeNu (Built-in Mathematica Symbol)

PrimeNu[n] gives the number of distinct primes \[Nu](n) in n.

PrimeOmega (Built-in Mathematica Symbol)

PrimeOmega[n] gives the number of prime factors counting multiplicities \[CapitalOmega](n) in n.

PrimePi (Built-in Mathematica Symbol)

PrimePi[x] gives the number of primes \[Pi] (x) less than or equal to x.

PrimitiveRoot (Built-in Mathematica Symbol)

PrimitiveRoot[n] gives the smallest primitive root of n.

SpheroidalRadialFactor (Built-in Mathematica Symbol)

SpheroidalRadialFactor[n, m, c] gives the spheroidal radial factor with degree n and order m.

SpheroidalS1Prime (Built-in Mathematica Symbol)

SpheroidalS1Prime[n, m, \[Gamma], z] gives the derivative with respect to z of the radial spheroidal function S_n^m, (1)(\[Gamma], z) of the first kind.

SpheroidalS2 (Built-in Mathematica Symbol)

SpheroidalS2[n, m, \[Gamma], z] gives the radial spheroidal function S_n^m, (2)(\[Gamma], z) of the second kind.

StringReverse (Built-in Mathematica Symbol)

StringReverse["string"] reverses the order of the characters in " string".

TimeConstrained (Built-in Mathematica Symbol)

TimeConstrained[expr, t] evaluates expr, stopping after t seconds. TimeConstrained[expr, t, failexpr] returns failexpr if the time constraint is not met.