 | ECS #520: A simple regular expression in a labelled universe |
| Introduction | Examples | Search | Submit | Help | Links |
1. Description
No description available
2. Specification
This labelled structure is specified as S in
\displaystyle
\left\{ S={\rm Prod} \left( {\rm Sequence} \left( Z \right) ,{\rm
Sequence} \left( {\rm Union} \left( Z,Z,Z \right) \right) \right)
\right\}
other formats
3. Coefficients
3.1. First terms
3.2. Recurrence
\displaystyle
\left\{ \left( 3\,{n}^{2}+9\,n+6 \right) f \left( n \right) + \left(
-4\,n-8 \right) f \left( n+1 \right) +f \left( n+2 \right) =0,f \left( 0
\right) =1,f \left( 1 \right) =4 \right\}
other formats
3.3. Closed form
\displaystyle
\left( -1/2+1/2\,{3}^{n+1} \right) n!
other formats
3.4. Asymptotics
4. Exponential generating function
\displaystyle
{\frac {1}{ \left( -1+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).