Emirps containing only the digits 1 and 3.

Terms

a(0) =13a(1) =31a(2) =113a(3) =311a(4) =113131a(5) =131311a(6) =1131131a(7) =1133131a(8) =1133333a(9) =1311311a(10) =1313311a(11) =1331333a(12) =1333313a(13) =3111313a(14) =3131113a(15) =3133331a(16) =3331331a(17) =3333311a(18) =11113111a(19) =11131111a(20) =11311133a(21) =11313311a(22) =11331311a(23) =11333131a(24) =13131133a(25) =13133311a(26) =31111313a(27) =31311113a(28) =33111311a(29) =33113131