Number of alternating permutations on 2n+1 letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
A217800
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) =1274a(5) =17136a(6) =255816a(7) =4124406a(8) =70549050a(9) =1264752060a(10) =23555382240a(11) =452806924752
External references
- oeis: A217800