Number of n-element unlabeled N-free posets.

A202182

Number of n-element unlabeled N-free posets.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =15a(4) =49a(5) =180a(6) =715a(7) =3081a(8) =14217a(9) =69905a(10) =363926a(11) =1996922a(12) =1150036a(13) =69269925

External references