A217807 Number of alternating permutations on 2n letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
1, 4, 29, 292, 3620, 51866, 827415, 14350467, 266218320
Offset: 1
Links
- Andrew R. Conway, Anthony J. Guttmann, Paul Zinn-Justin, 1324-avoiding permutations revisited arXiv:1709.01248 [math.CO], 2017.
- J. B. Lewis, Pattern Avoidance for Alternating Permutations and Reading Words of Tableaux, Ph. D. Dissertation, Department of Mathematics, MIT, 2012.
Extensions
a(7)-a(9) from Lars Blomberg, Feb 17 2018