Triangular numbers whose index is a multiple of the sum of their digits.

Terms

a(0) =1a(1) =10a(2) =21a(3) =45a(4) =55a(5) =120a(6) =171a(7) =300a(8) =465a(9) =666a(10) =820a(11) =1035a(12) =1485a(13) =1830a(14) =2016a(15) =2211a(16) =2628a(17) =2850a(18) =2926a(19) =3321a(20) =4095a(21) =5050a(22) =5565a(23) =5886a(24) =7260a(25) =8001a(26) =8911a(27) =10011a(28) =10440a(29) =13203