Difference between the largest prime < 10^n (A003618) and 10^n.

Terms

a(0) =3a(1) =3a(2) =3a(3) =27a(4) =9a(5) =17a(6) =9a(7) =11a(8) =63a(9) =33a(10) =23a(11) =11a(12) =29a(13) =27a(14) =11a(15) =63a(16) =3a(17) =11a(18) =39a(19) =11a(20) =101a(21) =27a(22) =23a(23) =257a(24) =123a(25) =141a(26) =99a(27) =209a(28) =27a(29) =11