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

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =8a(5) =20a(6) =60a(7) =216a(8) =898a(9) =4174a(10) =21202a(11) =116064a(12) =678714a(13) =4213830a(14) =27644814a(15) =190899932a(16) =1382959532a(17) =10480143744a(18) =82864872388a(19) =682076810340