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

Terms

a(0) =2a(1) =3a(2) =3a(3) =3a(4) =3a(5) =21a(6) =53a(7) =69a(8) =81a(9) =139a(10) =143a(11) =223a(12) =233a(13) =261a(14) =261a(15) =399a(16) =553a(17) =609a(18) =659a(19) =673a(20) =1017a(21) =1187a(22) =1357a(23) =1571a(24) =1641a(25) =1839a(26) =2151a(27) =2191a(28) =2499a(29) =2511