 | ECS #145 |
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1. Description
No description available
2. Specification
This unlabelled structure is specified as S in
\displaystyle
\left\{ B={\rm Sequence} \left( E \right) ,C={\rm Sequence} \left( E,1
\leq {\rm card} \right) ,E={\rm Prod} \left( Z,B \right) ,S={\rm
Sequence} \left( C \right) \right\}
other formats
3. Coefficients
3.1. First terms
3.2. Recurrence
\displaystyle
\left\{ \left( 2+4\,n \right) f \left( n \right) + \left( -n-1
\right) f \left( n+1 \right) =0,f \left( 0 \right) =1,f \left( 1
\right) =1 \right\}
other formats
3.3. Closed form
\displaystyle
{\frac {{2}^{-1+2\,n}\Gamma \left( n+1/2 \right) }{\sqrt {\pi }\Gamma
\left( n+1 \right) }}
other formats
3.4. Asymptotics
4. Ordinary generating function
\displaystyle
-{\frac {-1/2-1/2\,\sqrt {1-4\,x}}{\sqrt {1-4\,x}}}
other formats
5. References
6. Random structure
Search a combinatorial structure by: (firstTerms should be a sequence of integers, separated by commas).