Triangular numbers with sum of digits = 21.

Terms

a(0) =1596a(1) =2775a(2) =3486a(3) =3828a(4) =4278a(5) =4656a(6) =5565a(7) =6555a(8) =7626a(9) =8256a(10) =9453a(11) =14196a(12) =15753a(13) =16653a(14) =17391a(15) =18336a(16) =21945a(17) =22791a(18) =23871a(19) =24753a(20) =28920a(21) =32385a(22) =34716a(23) =37128a(24) =38226a(25) =39621a(26) =40755a(27) =42195a(28) =43365a(29) =44850