Difference between largest n-digit prime and smallest (n+1)-digit prime.

Terms

a(0) =4a(1) =4a(2) =12a(3) =34a(4) =12a(5) =20a(6) =28a(7) =18a(8) =70a(9) =52a(10) =26a(11) =50a(12) =66a(13) =58a(14) =48a(15) =124a(16) =6a(17) =14a(18) =90a(19) =50a(20) =218a(21) =36a(22) =140a(23) =264a(24) =136a(25) =208a(26) =202a(27) =540a(28) =346a(29) =68