Number of balanced set partitions of {1..n}.

Terms

a(0) =0a(1) =1a(2) =0a(3) =3a(4) =3a(5) =10a(6) =60a(7) =210a(8) =700a(9) =3556a(10) =19845a(11) =105567a(12) =550935a(13) =3120832a(14) =19432413a(15) =127949250a(16) =858963105a(17) =5882733142a(18) =41636699676a(19) =307105857344