Triangle read by rows: T(n, k) = 10^(n-1) - 1 + k*floor(9*10^(n-1)/n), for 1 <= k <= n.

Terms

a(0) =9a(1) =54a(2) =99a(3) =399a(4) =699a(5) =999a(6) =3249a(7) =5499a(8) =7749a(9) =9999a(10) =27999a(11) =45999a(12) =63999a(13) =81999a(14) =99999a(15) =249999a(16) =399999a(17) =549999a(18) =699999a(19) =849999a(20) =999999a(21) =2285713a(22) =3571427a(23) =4857141a(24) =6142855a(25) =7428569a(26) =8714283a(27) =9999997a(28) =21249999a(29) =32499999