Difference between (first Chen prime > 10^n) and 10^n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =9a(4) =7a(5) =19a(6) =37a(7) =19a(8) =7a(9) =7a(10) =19a(11) =19a(12) =61a(13) =687a(14) =97a(15) =91a(16) =79a(17) =13a(18) =79a(19) =97a(20) =151a(21) =217a(22) =427a(23) =253a(24) =667a(25) =13a(26) =127a(27) =427a(28) =457a(29) =577