 | ECS #421 |
| Introduction | Examples | Search | Submit | Help | Links |
1. Description
No description available
2. Specification
This unlabelled structure is specified as S in
\displaystyle
\left\{ B={\rm Prod} \left( Z,S \right) ,C={\rm Sequence} \left( B,1
\leq {\rm card} \right) ,S={\rm Union} \left( C,Z \right) \right\}
other formats
3. Coefficients
3.1. First terms
3.2. Recurrence
\displaystyle
\left\{ \left( n-1 \right) f \left( n \right) + \left( -1-2\,n
\right) f \left( 1+n \right) + \left( -n-2 \right) f \left( n+2
\right) + \left( -7-2\,n \right) f \left( n+3 \right) + \left( 5+n
\right) f \left( n+4 \right) =0,f \left( 0 \right) =0,f \left( 1
\right) =1,f \left( 2 \right) =1,f \left( 3 \right) =1 \right\}
other formats
3.3. Asymptotics
4. Ordinary generating function
\displaystyle
-1/2\,{\frac {-1+{x}^{2}+x+\sqrt {1-{x}^{2}-2\,x+{x}^{4}-2\,{x}^{3}}}{x
}}+x
other formats
5. References
6. Random structure
Search a combinatorial structure by: (firstTerms should be a sequence of integers, separated by commas).