Partial sums of A278742.

Terms

a(0) =1a(1) =3a(2) =6a(3) =16a(4) =27a(5) =39a(6) =59a(7) =89a(8) =189a(9) =299a(10) =499a(11) =799a(12) =1799a(13) =2899a(14) =4899a(15) =6999a(16) =9999a(17) =19999a(18) =39999a(19) =69999a(20) =169999a(21) =279999a(22) =399999a(23) =599999a(24) =899999a(25) =1899999a(26) =2999999a(27) =4999999a(28) =7999999a(29) =17999999