a(n) = b(n) + d(n), where b(n) = (n-th Lucas number > 3) and d(n) = (n-th non-Lucas number).

Terms

a(0) =6a(1) =12a(2) =17a(3) =26a(4) =38a(5) =57a(6) =88a(7) =136a(8) =213a(9) =337a(10) =537a(11) =860a(12) =1383a(13) =2227a(14) =3592a(15) =5800a(16) =9372a(17) =15151a(18) =24501a(19) =39629a(20) =64106a(21) =103710a(22) =167791a(23) =271474a(24) =439236a(25) =710680a(26) =1149885a(27) =1860533a(28) =3010385a(29) =4870884