Number of alternating permutations on 2n+1 letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
A217802
Number of alternating permutations on 2n+1 letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
Terms
- a(0) =1a(1) =2a(2) =12a(3) =110a(4) =1285a(5) =17653a(6) =272832a(7) =4615282a(8) =83898083
External references
- oeis: A217802