 | ECS #403 |
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1. Description
No description available
2. Specification
This unlabelled structure is specified as S in
\displaystyle
\left\{ S={\rm Sequence} \left( {\rm Union} \left( Z,{\rm Prod}
\left( {\rm Union} \left( Z,Z,Z,Z \right) ,{\rm Sequence} \left( Z
\right) \right) \right) \right) \right\}
other formats
3. Coefficients
3.1. First terms
3.2. Recurrence
\displaystyle
\left\{ f \left( n \right) -6\,f \left( n+1 \right) +f \left( n+2
\right) =0,f \left( 0 \right) =1,f \left( 1 \right) =5 \right\}
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3.3. Closed form
\displaystyle
\sum _{\alpha={\rm RootOf} \left( 1-6\,{\rm \_Z}+{{\rm \_Z}}^{2}
\right) }1/8\, \left( 1+\alpha \right) {\alpha}^{-1-n}
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3.4. Asymptotics
4. Ordinary generating function
\displaystyle
-{\frac {-1+x}{1-6\,x+{x}^{2}}}
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5. References
6. Random structure
Search a combinatorial structure by: (firstTerms should be a sequence of integers, separated by commas).