${\displaystyle k>0}$ parametr kształtu (liczba całkowita)
${\displaystyle \lambda >0}$ częstość (liczba rzeczywista)
alt.: ${\displaystyle \theta =1/\lambda >0}$ parametr skali (liczba rzeczywista)

${\displaystyle x\in [0;\infty )}$

${\displaystyle {\frac {\lambda ^{k}x^{k-1}e^{-\lambda x}}{(k-1)!\,}}}$

${\displaystyle {\frac {\gamma (k,\lambda x)}{(k-1)!}}=1-\sum _{n=0}^{k-1}e^{-\lambda x}(\lambda x)^{n}/n!}$

${\displaystyle k/\lambda }$

Nie da się zapisać w prostej postaci

${\displaystyle (k-1)/\lambda }$ dla ${\displaystyle k\geqslant 1}$

${\displaystyle k/\lambda ^{2}}$

${\displaystyle {\frac {2}{\sqrt {k}}}}$

${\displaystyle {\frac {6}{k}}}$

${\displaystyle k/\lambda +(k-1)\ln(\lambda )+\ln((k-1)!)}$
${\displaystyle +(1-k)\psi (k)}$

${\displaystyle (1-t/\lambda )^{-k}}$ dla ${\displaystyle t<\lambda }$

${\displaystyle (1-it/\lambda )^{-k}}$

Agner Krarup Erlang