Concatenation of n-th nonprime and n-th prime.

Terms

a(0) =12a(1) =43a(2) =65a(3) =87a(4) =911a(5) =1013a(6) =1217a(7) =1419a(8) =1523a(9) =1629a(10) =1831a(11) =2037a(12) =2141a(13) =2243a(14) =2447a(15) =2553a(16) =2659a(17) =2761a(18) =2867a(19) =3071a(20) =3273a(21) =3379a(22) =3483a(23) =3589a(24) =3697a(25) =38101a(26) =39103a(27) =40107a(28) =42109a(29) =44113