Triangular numbers with strictly increasing sum of digits.

Terms

a(0) =1a(1) =3a(2) =6a(3) =28a(4) =66a(5) =78a(6) =378a(7) =496a(8) =1596a(9) =5778a(10) =5995a(11) =8778a(12) =47895a(13) =58996a(14) =196878a(15) =468996a(16) =887778a(17) =1788886a(18) =4896885a(19) =5897895a(20) =13999986a(21) =15997996a(22) =38997696a(23) =88877778a(24) =179977878a(25) =189978778a(26) =398988876a(27) =686999778a(28) =1699998895a(29) =5779898886