Proper noun
von Mangoldt function
(mathematics) A certain arithmetic function that is neither multiplicative nor additive. It is denoted by Λ(n) and defined as :
Λ
(
n
)
=
{
log
p
if
n
=
p
k
for some prime
p
and integer
k
≥
1
,
0
otherwise.
{\displaystyle \Lambda (n)={\begin{cases}\log p&{\mbox{if }}n=p^{k}{\mbox{ for some prime }}p{\mbox{ and integer }}k\geq 1,\\0&{\mbox{otherwise.}}\end{cases}}}