( a ) n <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b"> <apply id="p1.1.m1.1.1.1.cmml" xref="p1.1.m1.1.1.6"> <csymbol cd="dlmf" id="p1.1.m1.1.1.1.1.cmml" xref="p1.1.m1.1.1.2">Pochhammer</csymbol> <ci id="p1.1.m1.1.1.3.cmml" xref="p1.1.m1.1.1.3">𝑎</ci> <ci id="p1.1.m1.1.1.5.1.cmml" xref="p1.1.m1.1.1.5.1">𝑛</ci> </apply> </annotation-xml> {\displaystyle{\displaystyle{\left(\NVar{a}\right)_{\NVar{n}}}}}
! <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b"> <factorial id="p1.1.m1.1.1.cmml" xref="p1.1.m1.1.1"/> </annotation-xml> {\displaystyle{\displaystyle!}}
z <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b"> <ci id="p1.1.m1.1.1.cmml" xref="p1.1.m1.1.1">𝑧</ci> </annotation-xml> {\displaystyle{\displaystyle z}}
k <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b"> <ci id="p1.1.m1.1.1.cmml" xref="p1.1.m1.1.1">𝑘</ci> </annotation-xml> {\displaystyle{\displaystyle k}}
n <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b"> <ci id="p1.1.m1.1.1.cmml" xref="p1.1.m1.1.1">𝑛</ci> </annotation-xml> {\displaystyle{\displaystyle n}}