Av(1234, 1243, 2413, 3142)
View Raw Data
Generating Function
\(\displaystyle \frac{\left(2 x -1\right) \left(x^{3}-2 x^{2}+3 x -1\right) \left(x -1\right)^{2}}{5 x^{6}-20 x^{5}+39 x^{4}-41 x^{3}+25 x^{2}-8 x +1}\)
Counting Sequence
1, 1, 2, 6, 20, 64, 197, 597, 1805, 5466, 16577, 50308, 152705, 463538, 1407099, ...
Implicit Equation for the Generating Function
\(\displaystyle \left(5 x^{6}-20 x^{5}+39 x^{4}-41 x^{3}+25 x^{2}-8 x +1\right) F \! \left(x \right)-\left(2 x -1\right) \left(x^{3}-2 x^{2}+3 x -1\right) \left(x -1\right)^{2} = 0\)
Recurrence
\(\displaystyle a \! \left(0\right) = 1\)
\(\displaystyle a \! \left(1\right) = 1\)
\(\displaystyle a \! \left(2\right) = 2\)
\(\displaystyle a \! \left(3\right) = 6\)
\(\displaystyle a \! \left(4\right) = 20\)
\(\displaystyle a \! \left(5\right) = 64\)
\(\displaystyle a \! \left(6\right) = 197\)
\(\displaystyle a \! \left(n +6\right) = -5 a \! \left(n \right)+20 a \! \left(n +1\right)-39 a \! \left(n +2\right)+41 a \! \left(n +3\right)-25 a \! \left(n +4\right)+8 a \! \left(n +5\right), \quad n \geq 7\)
Explicit Closed Form
\(\displaystyle -\frac{1751 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =1\right)^{-n +4}}{829}-\frac{1751 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =2\right)^{-n +4}}{829}-\frac{1751 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =3\right)^{-n +4}}{829}-\frac{1751 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =4\right)^{-n +4}}{829}-\frac{1751 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =5\right)^{-n +4}}{829}-\frac{1751 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =6\right)^{-n +4}}{829}+\frac{6203 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =1\right)^{-n +3}}{829}+\frac{6203 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =2\right)^{-n +3}}{829}+\frac{6203 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =3\right)^{-n +3}}{829}+\frac{6203 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =4\right)^{-n +3}}{829}+\frac{6203 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =5\right)^{-n +3}}{829}+\frac{6203 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =6\right)^{-n +3}}{829}-\frac{52534 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =1\right)^{-n +2}}{4145}-\frac{52534 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =2\right)^{-n +2}}{4145}-\frac{52534 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =3\right)^{-n +2}}{4145}-\frac{52534 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =4\right)^{-n +2}}{4145}-\frac{52534 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =5\right)^{-n +2}}{4145}-\frac{52534 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =6\right)^{-n +2}}{4145}+\frac{43742 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =1\right)^{-n +1}}{4145}+\frac{43742 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =2\right)^{-n +1}}{4145}+\frac{43742 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =3\right)^{-n +1}}{4145}+\frac{43742 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =4\right)^{-n +1}}{4145}+\frac{43742 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =5\right)^{-n +1}}{4145}+\frac{43742 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =6\right)^{-n +1}}{4145}+\frac{3392 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =1\right)^{-n -1}}{4145}+\frac{3392 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =2\right)^{-n -1}}{4145}+\frac{3392 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =3\right)^{-n -1}}{4145}+\frac{3392 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =4\right)^{-n -1}}{4145}+\frac{3392 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =5\right)^{-n -1}}{4145}+\frac{3392 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =6\right)^{-n -1}}{4145}-\frac{3796 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =1\right)^{-n}}{829}-\frac{3796 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =2\right)^{-n}}{829}-\frac{3796 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =3\right)^{-n}}{829}-\frac{3796 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =4\right)^{-n}}{829}-\frac{3796 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =5\right)^{-n}}{829}-\frac{3796 \mathit{RootOf} \left(5 Z^{6}-20 Z^{5}+39 Z^{4}-41 Z^{3}+25 Z^{2}-8 Z +1, \mathit{index} =6\right)^{-n}}{829}+\left(\left\{\begin{array}{cc}\frac{2}{5} & n =0 \\ 0 & \text{otherwise} \end{array}\right.\right)\)

This specification was found using the strategy pack "Point Placements" and has 74 rules.

Found on January 18, 2022.

Finding the specification took 1 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_{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_{19}\! \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_{11}\! \left(x \right)\\ F_{10}\! \left(x \right) &= F_{1}\! \left(x \right)+F_{4}\! \left(x \right)\\ F_{11}\! \left(x \right) &= F_{12}\! \left(x \right)+F_{7}\! \left(x \right)\\ F_{12}\! \left(x \right) &= F_{13}\! \left(x \right)+F_{14}\! \left(x \right)+F_{18}\! \left(x \right)\\ F_{13}\! \left(x \right) &= 0\\ F_{14}\! \left(x \right) &= F_{15}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{15}\! \left(x \right) &= F_{16}\! \left(x \right)+F_{17}\! \left(x \right)\\ F_{16}\! \left(x \right) &= F_{4}\! \left(x \right)\\ F_{17}\! \left(x \right) &= F_{12}\! \left(x \right)\\ F_{18}\! \left(x \right) &= F_{4}\! \left(x \right) F_{7}\! \left(x \right)\\ F_{19}\! \left(x \right) &= F_{2}\! \left(x \right)+F_{20}\! \left(x \right)\\ F_{20}\! \left(x \right) &= F_{13}\! \left(x \right)+F_{21}\! \left(x \right)+F_{54}\! \left(x \right)\\ F_{21}\! \left(x \right) &= F_{22}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{22}\! \left(x \right) &= F_{23}\! \left(x \right)+F_{29}\! \left(x \right)\\ F_{23}\! \left(x \right) &= F_{24}\! \left(x \right)+F_{7}\! \left(x \right)\\ F_{24}\! \left(x \right) &= F_{25}\! \left(x \right)\\ F_{25}\! \left(x \right) &= F_{26}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{26}\! \left(x \right) &= F_{16}\! \left(x \right)+F_{27}\! \left(x \right)\\ F_{27}\! \left(x \right) &= F_{28}\! \left(x \right)\\ F_{28}\! \left(x \right) &= F_{25}\! \left(x \right)\\ F_{29}\! \left(x \right) &= F_{20}\! \left(x \right)+F_{30}\! \left(x \right)\\ F_{30}\! \left(x \right) &= 2 F_{13}\! \left(x \right)+F_{31}\! \left(x \right)+F_{35}\! \left(x \right)\\ F_{31}\! \left(x \right) &= F_{32}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{32}\! \left(x \right) &= F_{33}\! \left(x \right)+F_{34}\! \left(x \right)\\ F_{33}\! \left(x \right) &= F_{24}\! \left(x \right)\\ F_{34}\! \left(x \right) &= F_{30}\! \left(x \right)\\ F_{35}\! \left(x \right) &= F_{36}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{36}\! \left(x \right) &= F_{37}\! \left(x \right)+F_{49}\! \left(x \right)\\ F_{37}\! \left(x \right) &= F_{38}\! \left(x \right)\\ F_{38}\! \left(x \right) &= F_{13}\! \left(x \right)+F_{39}\! \left(x \right)+F_{48}\! \left(x \right)\\ F_{39}\! \left(x \right) &= F_{4}\! \left(x \right) F_{40}\! \left(x \right)\\ F_{40}\! \left(x \right) &= F_{41}\! \left(x \right)+F_{42}\! \left(x \right)\\ F_{41}\! \left(x \right) &= F_{28}\! \left(x \right)+F_{4}\! \left(x \right)\\ F_{42}\! \left(x \right) &= F_{38}\! \left(x \right)+F_{43}\! \left(x \right)\\ F_{43}\! \left(x \right) &= 2 F_{13}\! \left(x \right)+F_{35}\! \left(x \right)+F_{44}\! \left(x \right)\\ F_{44}\! \left(x \right) &= F_{4}\! \left(x \right) F_{45}\! \left(x \right)\\ F_{45}\! \left(x \right) &= F_{46}\! \left(x \right)+F_{47}\! \left(x \right)\\ F_{46}\! \left(x \right) &= F_{28}\! \left(x \right)\\ F_{47}\! \left(x \right) &= F_{43}\! \left(x \right)\\ F_{48}\! \left(x \right) &= F_{2}\! \left(x \right) F_{4}\! \left(x \right)\\ F_{49}\! \left(x \right) &= F_{50}\! \left(x \right)\\ F_{50}\! \left(x \right) &= F_{4}\! \left(x \right) F_{51}\! \left(x \right)\\ F_{51}\! \left(x \right) &= F_{52}\! \left(x \right)+F_{53}\! \left(x \right)\\ F_{52}\! \left(x \right) &= F_{38}\! \left(x \right)\\ F_{53}\! \left(x \right) &= F_{50}\! \left(x \right)\\ F_{54}\! \left(x \right) &= F_{4}\! \left(x \right) F_{55}\! \left(x \right)\\ F_{55}\! \left(x \right) &= F_{56}\! \left(x \right)+F_{57}\! \left(x \right)\\ F_{56}\! \left(x \right) &= F_{2}\! \left(x \right)+F_{38}\! \left(x \right)\\ F_{57}\! \left(x \right) &= F_{58}\! \left(x \right)+F_{70}\! \left(x \right)\\ F_{58}\! \left(x \right) &= F_{59}\! \left(x \right)\\ F_{59}\! \left(x \right) &= F_{4}\! \left(x \right) F_{60}\! \left(x \right)\\ F_{60}\! \left(x \right) &= F_{61}\! \left(x \right)+F_{63}\! \left(x \right)\\ F_{61}\! \left(x \right) &= F_{2}\! \left(x \right)+F_{62}\! \left(x \right)\\ F_{62}\! \left(x \right) &= F_{48}\! \left(x \right)\\ F_{63}\! \left(x \right) &= F_{58}\! \left(x \right)+F_{64}\! \left(x \right)\\ F_{64}\! \left(x \right) &= 2 F_{13}\! \left(x \right)+F_{65}\! \left(x \right)+F_{69}\! \left(x \right)\\ F_{65}\! \left(x \right) &= F_{4}\! \left(x \right) F_{66}\! \left(x \right)\\ F_{66}\! \left(x \right) &= F_{67}\! \left(x \right)+F_{68}\! \left(x \right)\\ F_{67}\! \left(x \right) &= F_{62}\! \left(x \right)\\ F_{68}\! \left(x \right) &= F_{64}\! \left(x \right)\\ F_{69}\! \left(x \right) &= F_{4}\! \left(x \right) F_{58}\! \left(x \right)\\ F_{70}\! \left(x \right) &= 2 F_{13}\! \left(x \right)+F_{69}\! \left(x \right)+F_{71}\! \left(x \right)\\ F_{71}\! \left(x \right) &= F_{4}\! \left(x \right) F_{72}\! \left(x \right)\\ F_{72}\! \left(x \right) &= F_{52}\! \left(x \right)+F_{73}\! \left(x \right)\\ F_{73}\! \left(x \right) &= F_{70}\! \left(x \right)\\ \end{align*}\)