Bell(n-1) - Fibonacci(n).

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =0a(5) =2a(6) =10a(7) =44a(8) =190a(9) =856a(10) =4106a(11) =21092a(12) =115886a(13) =678426a(14) =4213364a(15) =27644060a(16) =190898712a(17) =1382957558a(18) =10480140550a(19) =82864867220a(20) =682076801978