From descending subsequences of permutations.

A006219

From descending subsequences of permutations.

Terms

    a(0) =3a(1) =8a(2) =25a(3) =89a(4) =357a(5) =1602a(6) =7959a(7) =43127a(8) =250591a(9) =1537051a(10) =9827077

External references