Partitions of n labeled elements into subsets of two or three elements.

A227937

Partitions of n labeled elements into subsets of two or three elements.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =1a(4) =3a(5) =10a(6) =25a(7) =105a(8) =385a(9) =1540a(10) =7245a(11) =32725a(12) =164395a(13) =870870a(14) =4689685a(15) =27152125a(16) =161786625a(17) =997196200a(18) =6443061625a(19) =42702885225a(20) =292938721075

External references