a(n) = (a(n-1) + 1)*a(n-2).A006277a(n) = (a(n-1) + 1)*a(n-2).Terms a(0) =1a(1) =1a(2) =2a(3) =3a(4) =8a(5) =27a(6) =224a(7) =6075a(8) =1361024a(9) =8268226875External referencesoeis: A006277