Triangular numbers that have some nontrivial permutation of digits which is also triangular.

Terms

a(0) =120a(1) =153a(2) =210a(3) =253a(4) =325a(5) =351a(6) =496a(7) =946a(8) =1378a(9) =1485a(10) =1830a(11) =1891a(12) =2145a(13) =2415a(14) =2701a(15) =3081a(16) =3570a(17) =3655a(18) =3741a(19) =3916a(20) =4095a(21) =4371a(22) =4560a(23) =4851a(24) =4950a(25) =5356a(26) =5460a(27) =5565a(28) =5778a(29) =6555