a(n) = Lucas(n) concatenated with Fibonacci(n).

Terms

a(0) =20a(1) =11a(2) =31a(3) =42a(4) =73a(5) =115a(6) =188a(7) =2913a(8) =4721a(9) =7634a(10) =12355a(11) =19989a(12) =322144a(13) =521233a(14) =843377a(15) =1364610a(16) =2207987a(17) =35711597a(18) =57782584a(19) =93494181a(20) =151276765a(21) =2447610946a(22) =3960317711a(23) =6407928657a(24) =10368246368a(25) =16776175025a(26) =271443121393a(27) =439204196418a(28) =710647317811