Bell number A000110(n) minus Bessel number A006789(n).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =9a(6) =60a(7) =368a(8) =2218a(9) =13496a(10) =84010a(11) =538885a(12) =3576885a(13) =24624234a(14) =176021146a(15) =1306975716a(16) =10078487587a(17) =80670305273a(18) =669699040920