Number of alternating permutations on 2n letters that avoid a certain pattern of length 5 (see Lewis, 2012, Appendix, for precise definition).
A217820
Number of alternating permutations on 2n letters that avoid a certain pattern of length 5 (see Lewis, 2012, Appendix, for precise definition).
Terms
- a(0) =1a(1) =5a(2) =61a(3) =1194a(4) =30802a(5) =953088a(6) =33563745a(7) =1302192441
External references
- oeis: A217820