 | ECS #169 |
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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,1\leq {\rm card} \right) ,C={\rm
Sequence} \left( B,1\leq {\rm card} \right) ,E={\rm Sequence} \left( Z,
1\leq {\rm card} \right) ,S={\rm Union} \left( B,C \right) \right\}
other formats
3. Coefficients
3.1. First terms
3.2. Recurrence
\displaystyle
\left\{ 6\,f \left( n \right) -5\,f \left( n+1 \right) +f \left( n+2
\right) =0,f \left( 0 \right) =0,f \left( 1 \right) =2,f \left( 2
\right) =5 \right\}
other formats
3.3. Closed form
\displaystyle
{2}^{-1+n}+{3}^{-1+n}+\cases{-5/6&$n=0$\cr 0&otherwise\cr}
other formats
3.4. Asymptotics
4. Ordinary generating function
\displaystyle
-{\frac {x \left( -2+5\,x \right) }{ \left( -1+2\,x \right) \left( -1+
3\,x \right) }}
other formats
5. References
6. Random structure
Search a combinatorial structure by: (firstTerms should be a sequence of integers, separated by commas).