Floor( 10^n / sum(k=3..10^n, 1/k ) ).

Terms

a(0) =6a(1) =27a(2) =167a(3) =1206a(4) =9442a(5) =77563a(6) =658097a(7) =5714972a(8) =50503822a(9) =452425909a(10) =4097411586a(11) =37441633014a(12) =344698955565