Triangular numbers which are also happy numbers (cf. A007770).

Terms

a(0) =1a(1) =10a(2) =28a(3) =91a(4) =190a(5) =496a(6) =820a(7) =946a(8) =1128a(9) =1275a(10) =2080a(11) =2211a(12) =2485a(13) =3321a(14) =4278a(15) =8128a(16) =8256a(17) =8778a(18) =9591a(19) =9730a(20) =11476a(21) =12090a(22) =12880a(23) =13203a(24) =13366a(25) =13530a(26) =15753a(27) =16471a(28) =17205a(29) =17578