Av(1342, 1432, 2413, 3124)
Generating Function
\(\displaystyle -\frac{\left(x^{2}+2 x -1\right) \left(x -1\right)^{2}}{x^{5}-2 x^{4}-3 x^{3}+7 x^{2}-5 x +1}\)
Counting Sequence
1, 1, 2, 6, 20, 65, 206, 645, 2012, 6273, 19563, 61024, 190377, 593940, 1852986, ...
Implicit Equation for the Generating Function
\(\displaystyle \left(x^{5}-2 x^{4}-3 x^{3}+7 x^{2}-5 x +1\right) F \! \left(x \right)+\left(x^{2}+2 x -1\right) \left(x -1\right)^{2} = 0\)
Recurrence
\(\displaystyle a \! \left(0\right) = 1\)
\(\displaystyle a \! \left(1\right) = 1\)
\(\displaystyle a \! \left(2\right) = 2\)
\(\displaystyle a \! \left(3\right) = 6\)
\(\displaystyle a \! \left(4\right) = 20\)
\(\displaystyle a \! \left(n +5\right) = -a \! \left(n \right)+2 a \! \left(n +1\right)+3 a \! \left(n +2\right)-7 a \! \left(n +3\right)+5 a \! \left(n +4\right), \quad n \geq 5\)
\(\displaystyle a \! \left(1\right) = 1\)
\(\displaystyle a \! \left(2\right) = 2\)
\(\displaystyle a \! \left(3\right) = 6\)
\(\displaystyle a \! \left(4\right) = 20\)
\(\displaystyle a \! \left(n +5\right) = -a \! \left(n \right)+2 a \! \left(n +1\right)+3 a \! \left(n +2\right)-7 a \! \left(n +3\right)+5 a \! \left(n +4\right), \quad n \geq 5\)
Explicit Closed Form
\(\displaystyle \frac{2390 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =1\right)^{-n +3}}{25679}+\frac{2390 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =2\right)^{-n +3}}{25679}+\frac{2390 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =3\right)^{-n +3}}{25679}+\frac{2390 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =4\right)^{-n +3}}{25679}+\frac{2390 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =5\right)^{-n +3}}{25679}-\frac{3145 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =1\right)^{-n +2}}{25679}-\frac{3145 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =2\right)^{-n +2}}{25679}-\frac{3145 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =3\right)^{-n +2}}{25679}-\frac{3145 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =4\right)^{-n +2}}{25679}-\frac{3145 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =5\right)^{-n +2}}{25679}-\frac{8838 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =1\right)^{-n +1}}{25679}-\frac{8838 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =2\right)^{-n +1}}{25679}-\frac{8838 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =3\right)^{-n +1}}{25679}-\frac{8838 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =4\right)^{-n +1}}{25679}-\frac{8838 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =5\right)^{-n +1}}{25679}-\frac{1766 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =1\right)^{-n -1}}{25679}-\frac{1766 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =2\right)^{-n -1}}{25679}-\frac{1766 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =3\right)^{-n -1}}{25679}-\frac{1766 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =4\right)^{-n -1}}{25679}-\frac{1766 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =5\right)^{-n -1}}{25679}+\frac{14337 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =1\right)^{-n}}{25679}+\frac{14337 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =2\right)^{-n}}{25679}+\frac{14337 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =3\right)^{-n}}{25679}+\frac{14337 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =4\right)^{-n}}{25679}+\frac{14337 \mathit{RootOf} \left(Z^{5}-2 Z^{4}-3 Z^{3}+7 Z^{2}-5 Z +1, \mathit{index} =5\right)^{-n}}{25679}\)
This specification was found using the strategy pack "Point Placements" and has 43 rules.
Found on January 18, 2022.Finding the specification took 1 seconds.
Copy 43 equations to clipboard:
\(\begin{align*}
F_{0}\! \left(x \right) &= F_{1}\! \left(x \right)+F_{2}\! \left(x \right)\\
F_{1}\! \left(x \right) &= 1\\
F_{2}\! \left(x \right) &= F_{3}\! \left(x \right)\\
F_{3}\! \left(x \right) &= F_{4}\! \left(x \right) F_{5}\! \left(x \right)\\
F_{4}\! \left(x \right) &= x\\
F_{5}\! \left(x \right) &= F_{17}\! \left(x \right)+F_{6}\! \left(x \right)\\
F_{6}\! \left(x \right) &= F_{1}\! \left(x \right)+F_{7}\! \left(x \right)\\
F_{7}\! \left(x \right) &= F_{8}\! \left(x \right)\\
F_{8}\! \left(x \right) &= F_{4}\! \left(x \right) F_{9}\! \left(x \right)\\
F_{9}\! \left(x \right) &= F_{10}\! \left(x \right)+F_{6}\! \left(x \right)\\
F_{10}\! \left(x \right) &= F_{11}\! \left(x \right)+F_{14}\! \left(x \right)\\
F_{11}\! \left(x \right) &= F_{12}\! \left(x \right)\\
F_{12}\! \left(x \right) &= F_{13}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{13}\! \left(x \right) &= F_{1}\! \left(x \right)+F_{11}\! \left(x \right)\\
F_{14}\! \left(x \right) &= F_{15}\! \left(x \right)\\
F_{15}\! \left(x \right) &= F_{16}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{16}\! \left(x \right) &= F_{7}\! \left(x \right)\\
F_{17}\! \left(x \right) &= F_{18}\! \left(x \right)+F_{2}\! \left(x \right)\\
F_{18}\! \left(x \right) &= F_{19}\! \left(x \right)+F_{20}\! \left(x \right)+F_{37}\! \left(x \right)\\
F_{19}\! \left(x \right) &= 0\\
F_{20}\! \left(x \right) &= F_{21}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{21}\! \left(x \right) &= F_{22}\! \left(x \right)+F_{26}\! \left(x \right)\\
F_{22}\! \left(x \right) &= F_{23}\! \left(x \right)+F_{7}\! \left(x \right)\\
F_{23}\! \left(x \right) &= F_{24}\! \left(x \right)\\
F_{24}\! \left(x \right) &= F_{25}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{25}\! \left(x \right) &= F_{11}\! \left(x \right)\\
F_{26}\! \left(x \right) &= F_{18}\! \left(x \right)+F_{27}\! \left(x \right)\\
F_{27}\! \left(x \right) &= 2 F_{19}\! \left(x \right)+F_{28}\! \left(x \right)+F_{32}\! \left(x \right)\\
F_{28}\! \left(x \right) &= F_{29}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{29}\! \left(x \right) &= F_{30}\! \left(x \right)+F_{31}\! \left(x \right)\\
F_{30}\! \left(x \right) &= F_{23}\! \left(x \right)\\
F_{31}\! \left(x \right) &= F_{27}\! \left(x \right)\\
F_{32}\! \left(x \right) &= F_{33}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{33}\! \left(x \right) &= F_{34}\! \left(x \right)\\
F_{34}\! \left(x \right) &= F_{35}\! \left(x \right)\\
F_{35}\! \left(x \right) &= F_{36}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{36}\! \left(x \right) &= F_{2}\! \left(x \right)+F_{34}\! \left(x \right)\\
F_{37}\! \left(x \right) &= F_{38}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{38}\! \left(x \right) &= F_{17}\! \left(x \right)+F_{39}\! \left(x \right)\\
F_{39}\! \left(x \right) &= F_{34}\! \left(x \right)+F_{40}\! \left(x \right)\\
F_{40}\! \left(x \right) &= F_{41}\! \left(x \right)\\
F_{41}\! \left(x \right) &= F_{4}\! \left(x \right) F_{42}\! \left(x \right)\\
F_{42}\! \left(x \right) &= F_{18}\! \left(x \right)\\
\end{align*}\)