Difference between last prime < 10^n and 10^n is a record high.

Terms

a(0) =1a(1) =4a(2) =9a(3) =21a(4) =24a(5) =34a(6) =56a(7) =66a(8) =92a(9) =100a(10) =112a(11) =117a(12) =135a(13) =180a(14) =260a(15) =349a(16) =387a(17) =393a(18) =411a(19) =574a(20) =617a(21) =787a(22) =1209