Number of indecomposable set partitions of [1..n] without singletons.

A098742

Number of indecomposable set partitions of [1..n] without singletons.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =1a(4) =3a(5) =9a(6) =33a(7) =135a(8) =609a(9) =2985a(10) =15747a(11) =88761a(12) =531561a(13) =3366567a(14) =22462017a(15) =157363329a(16) =1154257683a(17) =8841865833a(18) =70573741857a(19) =585753925047

External references