Number of alternating permutations on 2n+1 letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
A217804
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) =16a(3) =168a(4) =2072a(5) =28298a(6) =414472a(7) =6387436a(8) =102316000
External references
- oeis: A217804