Number of permutations p of [n] such that 0p has a nonincreasing up-jump sequence and also has a nonincreasing down-jump sequence.
A288910
Number of permutations p of [n] such that 0p has a nonincreasing up-jump sequence and also has a nonincreasing down-jump sequence.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =18a(5) =69a(6) =303a(7) =1357a(8) =6552a(9) =31961a(10) =163587a(11) =839710a(12) =4485686a(13) =23917300a(14) =131366017a(15) =722130351a(16) =4059017880a(17) =22809880116a(18) =130713878478a(19) =748596353814
External references
- oeis: A288910