Av(12435, 12453, 14235, 14253, 14325, 14352, 14523, 14532, 21435, 21453)
Counting Sequence
1, 1, 2, 6, 24, 110, 542, 2800, 14966, 82074, 459208, 2610938, 15042218, 87621664, 515190026, ...
Implicit Equation for the Generating Function
\(\displaystyle -F \left(x
\right)^{3}+\left(x +2\right) F \left(x
\right)^{2}-3 x F \! \left(x \right)+x -1 = 0\)
Recurrence
\(\displaystyle a \! \left(0\right) = 1\)
\(\displaystyle a \! \left(1\right) = 1\)
\(\displaystyle a \! \left(2\right) = 2\)
\(\displaystyle a \! \left(3\right) = 6\)
\(\displaystyle a \! \left(4\right) = 24\)
\(\displaystyle a \! \left(5\right) = 110\)
\(\displaystyle a \! \left(n +6\right) = \frac{5 \left(n -1\right) n a \! \left(n \right)}{7 \left(n +6\right) \left(n +5\right)}-\frac{3 n \left(15 n +11\right) a \! \left(n +1\right)}{7 \left(n +6\right) \left(n +5\right)}+\frac{6 \left(71 n +120\right) \left(n +1\right) a \! \left(n +2\right)}{35 \left(n +6\right) \left(n +5\right)}-\frac{\left(197 n^{2}+301 n -606\right) a \! \left(n +3\right)}{35 \left(n +6\right) \left(n +5\right)}+\frac{6 \left(3 n^{2}-55 n -254\right) a \! \left(n +4\right)}{35 \left(n +6\right) \left(n +5\right)}+\frac{3 \left(11 n +52\right) a \! \left(n +5\right)}{5 \left(n +6\right)}, \quad n \geq 6\)
\(\displaystyle a \! \left(1\right) = 1\)
\(\displaystyle a \! \left(2\right) = 2\)
\(\displaystyle a \! \left(3\right) = 6\)
\(\displaystyle a \! \left(4\right) = 24\)
\(\displaystyle a \! \left(5\right) = 110\)
\(\displaystyle a \! \left(n +6\right) = \frac{5 \left(n -1\right) n a \! \left(n \right)}{7 \left(n +6\right) \left(n +5\right)}-\frac{3 n \left(15 n +11\right) a \! \left(n +1\right)}{7 \left(n +6\right) \left(n +5\right)}+\frac{6 \left(71 n +120\right) \left(n +1\right) a \! \left(n +2\right)}{35 \left(n +6\right) \left(n +5\right)}-\frac{\left(197 n^{2}+301 n -606\right) a \! \left(n +3\right)}{35 \left(n +6\right) \left(n +5\right)}+\frac{6 \left(3 n^{2}-55 n -254\right) a \! \left(n +4\right)}{35 \left(n +6\right) \left(n +5\right)}+\frac{3 \left(11 n +52\right) a \! \left(n +5\right)}{5 \left(n +6\right)}, \quad n \geq 6\)
This specification was found using the strategy pack "Point Placements Tracked Fusion" and has 31 rules.
Found on January 23, 2022.Finding the specification took 149 seconds.
Copy 31 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_{30}\! \left(x \right) F_{4}\! \left(x \right)\\
F_{4}\! \left(x \right) &= F_{5}\! \left(x , 1\right)\\
F_{5}\! \left(x , y\right) &= F_{24}\! \left(x , y\right)+F_{6}\! \left(x , y\right)\\
F_{6}\! \left(x , y\right) &= F_{1}\! \left(x \right)+F_{7}\! \left(x , y\right)\\
F_{7}\! \left(x , y\right) &= F_{8}\! \left(x , y\right)\\
F_{8}\! \left(x , y\right) &= F_{21}\! \left(x , y\right) F_{9}\! \left(x , y\right)\\
F_{9}\! \left(x , y\right) &= F_{10}\! \left(x , y\right)+F_{6}\! \left(x , y\right)\\
F_{10}\! \left(x , y\right) &= F_{11}\! \left(x , y\right)+F_{7}\! \left(x , y\right)\\
F_{11}\! \left(x , y\right) &= F_{12}\! \left(x , y\right)\\
F_{12}\! \left(x , y\right) &= F_{13}\! \left(x , y\right) F_{21}\! \left(x , y\right)\\
F_{13}\! \left(x , y\right) &= F_{14}\! \left(x , y\right)+F_{22}\! \left(x , y\right)\\
F_{14}\! \left(x , y\right) &= F_{15}\! \left(x , y\right)\\
F_{15}\! \left(x , y\right) &= F_{16}\! \left(x , y\right) F_{21}\! \left(x , y\right) F_{9}\! \left(x , y\right)\\
F_{17}\! \left(x , y\right) &= F_{16}\! \left(x , y\right) F_{21}\! \left(x , y\right) F_{6}\! \left(x , y\right)\\
F_{17}\! \left(x , y\right) &= F_{18}\! \left(x , y\right)\\
F_{19}\! \left(x , y\right) &= F_{18}\! \left(x , y\right)+F_{6}\! \left(x , y\right)\\
F_{20}\! \left(x , y\right) &= F_{19}\! \left(x , y\right) F_{21}\! \left(x , y\right)\\
F_{20}\! \left(x , y\right) &= F_{7}\! \left(x , y\right)\\
F_{21}\! \left(x , y\right) &= y x\\
F_{22}\! \left(x , y\right) &= F_{23}\! \left(x , y\right) F_{6}\! \left(x , y\right)\\
F_{23}\! \left(x , y\right) &= F_{8}\! \left(x , y\right)\\
F_{24}\! \left(x , y\right) &= F_{25}\! \left(x , y\right)\\
F_{25}\! \left(x , y\right) &= F_{26}\! \left(x , y\right) F_{30}\! \left(x \right)\\
F_{26}\! \left(x , y\right) &= F_{27}\! \left(x , y\right)+F_{28}\! \left(x , y\right)\\
F_{27}\! \left(x , y\right) &= -\frac{-y F_{5}\! \left(x , y\right)+F_{5}\! \left(x , 1\right)}{-1+y}\\
F_{28}\! \left(x , y\right) &= F_{29}\! \left(x , y\right)\\
F_{29}\! \left(x , y\right) &= F_{16}\! \left(x , y\right) F_{21}\! \left(x , y\right) F_{27}\! \left(x , y\right)\\
F_{30}\! \left(x \right) &= x\\
\end{align*}\)