Least positive integer k such that Sum_{i=1..k} phi(i) >= 10^n.

Terms

a(0) =1a(1) =5a(2) =18a(3) =57a(4) =181a(5) =573a(6) =1814a(7) =5736a(8) =18138a(9) =57357a(10) =181380a(11) =573574a(12) =1813799a(13) =5735737a(14) =18137993a(15) =57357372a(16) =181379937a(17) =573573721a(18) =1813799364a(19) =5735737209a(20) =18137993642a(21) =57357372095a(22) =181379936423a(23) =573573720955