CatalanNumber[z] == Pochhammer[z + 1, z]/Gamma[z + 2]

Cell[BoxData[RowBox[List[RowBox[List["CatalanNumber", "[", "z", "]"]], "\[Equal]", FractionBox[RowBox[List["Pochhammer", "[", RowBox[List[RowBox[List["z", "+", "1"]], ",", "z"]], "]"]], RowBox[List["Gamma", "[", RowBox[List["z", "+", "2"]], "]"]]]]]]]

<math xmlns='http://www.w3.org/1998/Math/MathML' mathematica:form='TraditionalForm' xmlns:mathematica='http://www.wolfram.com/XML/'> <semantics> <mrow> <msub> <semantics> <mi> C </mi> <annotation encoding='Mathematica'> TagBox[&quot;C&quot;, CatalanNumber] </annotation> </semantics> <mi> z </mi> </msub> <mo> &#63449; </mo> <mfrac> <semantics> <msub> <mrow> <mo> ( </mo> <mrow> <mi> z </mi> <mo> + </mo> <mn> 1 </mn> </mrow> <mo> ) </mo> </mrow> <mi> z </mi> </msub> <annotation encoding='Mathematica'> TagBox[SubscriptBox[RowBox[List[&quot;(&quot;, RowBox[List[&quot;z&quot;, &quot;+&quot;, &quot;1&quot;]], &quot;)&quot;]], &quot;z&quot;], Pochhammer] </annotation> </semantics> <mrow> <mi> &#915; </mi> <mo> &#8289; </mo> <mo> ( </mo> <mrow> <mi> z </mi> <mo> + </mo> <mn> 2 </mn> </mrow> <mo> ) </mo> </mrow> </mfrac> </mrow> <annotation-xml encoding='MathML-Content'> <apply> <eq /> <apply> <ci> CatalanNumber </ci> <ci> z </ci> </apply> <apply> <times /> <apply> <ci> Pochhammer </ci> <apply> <plus /> <ci> z </ci> <cn type='integer'> 1 </cn> </apply> <ci> z </ci> </apply> <apply> <power /> <apply> <ci> Gamma </ci> <apply> <plus /> <ci> z </ci> <cn type='integer'> 2 </cn> </apply> </apply> <cn type='integer'> -1 </cn> </apply> </apply> </apply> </annotation-xml> </semantics> </math>

Cell[BoxData[RowBox[List[RowBox[List["HoldPattern", "[", RowBox[List["CatalanNumber", "[", "z_", "]"]], "]"]], "\[RuleDelayed]", FractionBox[RowBox[List["Pochhammer", "[", RowBox[List[RowBox[List["z", "+", "1"]], ",", "z"]], "]"]], RowBox[List["Gamma", "[", RowBox[List["z", "+", "2"]], "]"]]]]]]]

2007-05-02