numtheory/tau(deprecated) - Help

numtheory

 tau
 number of divisors

 Calling Sequence tau(n) sigma[0] (n)

Parameters

 n - integer

Description

 • Important: The numtheory[tau] command has been deprecated.  Use the superseding command NumberTheory[SumOfDivisors] instead.
 • The function tau(n) will compute the number of positive divisors of n.
 • The command with(numtheory,tau) allows the use of the abbreviated form of this command.

Examples

 > $\mathrm{with}\left(\mathrm{numtheory}\right):$
 > $\mathrm{divisors}\left(-9\right)$
 $\left\{{1}{,}{3}{,}{9}\right\}$ (1)
 > $\mathrm{τ}\left(-9\right)$
 ${3}$ (2)
 > $\mathrm{divisors}\left(1\right)$
 $\left\{{1}\right\}$ (3)
 > $\mathrm{τ}\left(0\right)$
 ${0}$ (4)
 > $\mathrm{τ}\left(1\right)$
 ${1}$ (5)
 > $\mathrm{divisors}\left(20\right)$
 $\left\{{1}{,}{2}{,}{4}{,}{5}{,}{10}{,}{20}\right\}$ (6)
 > $\mathrm{τ}\left(20\right)$
 ${6}$ (7)
 > $\mathrm{σ}[0]\left(20\right)$
 ${6}$ (8)