Related to graded partially ordered sets.

A001830

Related to graded partially ordered sets.

Terms

    a(0) =1a(1) =7a(2) =61a(3) =661a(4) =8953a(5) =152917a(6) =3334921a(7) =94354981a(8) =3528929353a(9) =177999003157

External references