Number of ways to partition an n-set into subsets of equal size.

Terms

a(0) =1a(1) =2a(2) =2a(3) =5a(4) =2a(5) =27a(6) =2a(7) =142a(8) =282a(9) =1073a(10) =2a(11) =32034a(12) =2a(13) =136853a(14) =1527528a(15) =4661087a(16) =2a(17) =227932993a(18) =2a(19) =3689854456a(20) =36278688162a(21) =13749663293a(22) =2a(28) =2a(30) =2