Difference between 10^n and the first prime of gap 4 > 10^n.

Terms

a(0) =3a(1) =3a(2) =9a(3) =99a(4) =189a(5) =33a(6) =453a(7) =123a(8) =93a(9) =597a(10) =69a(11) =189a(12) =279a(13) =1173a(14) =399a(15) =1719a(16) =2733a(17) =2493a(18) =87a(19) =753a(20) =213a(21) =537a(22) =249a(23) =663a(24) =3309a(25) =123a(26) =279a(27) =597a(28) =2253a(29) =2853