a(1) = 3; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.

Terms

a(0) =3a(1) =7a(2) =9a(3) =51a(4) =57a(5) =103a(6) =119a(7) =121a(8) =183a(9) =293a(10) =301a(11) =351a(12) =447a(13) =479a(14) =577a(15) =741a(16) =839a(17) =1051a(18) =1277a(19) =1431a(20) =1633a(21) =1877a(22) =2043a(23) =2251a(24) =2303a(25) =2659a(26) =2937a(27) =3447a(28) =3897a(29) =3969