Av(12345, 12354, 12435, 13425, 21345, 21354, 21435, 23415, 31425, 32415)
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Counting Sequence
1, 1, 2, 6, 24, 110, 542, 2800, 14966, 82074, 459208, 2610938, 15042218, 87621664, 515190026, ...
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Implicit Equation for the Generating Function
\(\displaystyle -F \left(x \right)^{3}+\left(x +2\right) F \left(x \right)^{2}-3 x F \! \left(x \right)+x -1 = 0\)
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Recurrence
\(\displaystyle a \! \left(0\right) = 1\)
\(\displaystyle a \! \left(1\right) = 1\)
\(\displaystyle a \! \left(2\right) = 2\)
\(\displaystyle a \! \left(3\right) = 6\)
\(\displaystyle a \! \left(4\right) = 24\)
\(\displaystyle a \! \left(5\right) = 110\)
\(\displaystyle a \! \left(n +6\right) = \frac{5 \left(n -1\right) n a \! \left(n \right)}{7 \left(n +6\right) \left(n +5\right)}-\frac{3 n \left(15 n +11\right) a \! \left(n +1\right)}{7 \left(n +6\right) \left(n +5\right)}+\frac{6 \left(71 n +120\right) \left(n +1\right) a \! \left(n +2\right)}{35 \left(n +6\right) \left(n +5\right)}-\frac{\left(197 n^{2}+301 n -606\right) a \! \left(n +3\right)}{35 \left(n +6\right) \left(n +5\right)}+\frac{6 \left(3 n^{2}-55 n -254\right) a \! \left(n +4\right)}{35 \left(n +6\right) \left(n +5\right)}+\frac{3 \left(11 n +52\right) a \! \left(n +5\right)}{5 \left(n +6\right)}, \quad n \geq 6\)
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This specification was found using the strategy pack "Col Placements Tracked Fusion" and has 16 rules.

Found on January 22, 2022.

Finding the specification took 3 seconds.

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\(\begin{align*} F_{0}\! \left(x \right) &= F_{1}\! \left(x \right)+F_{2}\! \left(x \right)\\ F_{1}\! \left(x \right) &= 1\\ F_{2}\! \left(x \right) &= F_{3}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{3}\! \left(x \right) &= x\\ F_{4}\! \left(x \right) &= F_{1}\! \left(x \right)+F_{15}\! \left(x \right)+F_{5}\! \left(x \right)\\ F_{5}\! \left(x \right) &= F_{3}\! \left(x \right) F_{6}\! \left(x \right)\\ F_{6}\! \left(x \right) &= F_{7}\! \left(x , 1\right)\\ F_{7}\! \left(x , y\right) &= F_{1}\! \left(x \right)+F_{10}\! \left(x , y\right)+F_{11}\! \left(x , y\right)+F_{8}\! \left(x , y\right)\\ F_{8}\! \left(x , y\right) &= F_{3}\! \left(x \right) F_{9}\! \left(x , y\right)\\ F_{9}\! \left(x , y\right) &= \frac{y F_{7}\! \left(x , y\right)-F_{7}\! \left(x , 1\right)}{-1+y}\\ F_{10}\! \left(x , y\right) &= F_{3}\! \left(x \right) F_{9}\! \left(x , y\right)\\ F_{11}\! \left(x , y\right) &= F_{12}\! \left(x , y\right)\\ F_{12}\! \left(x , y\right) &= F_{13}\! \left(x , y\right) F_{14}\! \left(x , y\right) F_{7}\! \left(x , y\right)\\ F_{13}\! \left(x , y\right) &= y x\\ F_{14}\! \left(x , y\right) &= F_{1}\! \left(x \right)+F_{13}\! \left(x , y\right)\\ F_{15}\! \left(x \right) &= F_{3}\! \left(x \right) F_{6}\! \left(x \right)\\ \end{align*}\)