Number of partitions of an n-set into blocks of size <= n/2.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =10a(5) =26a(6) =166a(7) =652a(8) =3795a(9) =18755a(10) =112124a(11) =648649a(12) =4163743a(13) =27216840a(14) =190168577a(15) =1376119903a(16) =10468226150a(17) =82744297014a(18) =681863474058