Primes written in the factorial base.

Terms

a(0) =10a(1) =11a(2) =21a(3) =101a(4) =121a(5) =201a(6) =221a(7) =301a(8) =321a(9) =1021a(10) =1101a(11) =1201a(12) =1221a(13) =1301a(14) =1321a(15) =2021a(16) =2121a(17) =2201a(18) =2301a(19) =2321a(20) =3001a(21) =3101a(22) =3121a(23) =3221a(24) =4001a(25) =4021a(26) =4101a(27) =4121a(28) =4201a(29) =4221