Number of permutations p of [n] such that the up-down signature of p has nonnegative partial sums with a maximal value of two.
A320976
Number of permutations p of [n] such that the up-down signature of p has nonnegative partial sums with a maximal value of two.
Terms
- a(0) =0a(1) =1a(2) =3a(3) =24a(4) =101a(5) =862a(6) =4743a(7) =47216a(8) =322039a(9) =3744368a(10) =30517747a(11) =409498400a(12) =3884904379a(13) =59360223088a(14) =642766195887
External references
- oeis: A320976