Number of partitions of an n-set into boxes of size >2.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =11a(7) =36a(8) =92a(9) =491a(10) =2557a(11) =11353a(12) =60105a(13) =362506a(14) =2169246a(15) =13580815a(16) =91927435a(17) =650078097a(18) =4762023647a(19) =36508923530a(20) =292117087090