Triangular numbers that are also brilliant (A078972).

Terms

a(0) =6a(1) =10a(2) =15a(3) =21a(4) =253a(5) =703a(6) =1081a(7) =1711a(8) =1891a(9) =2701a(10) =3403a(11) =25651a(12) =34453a(13) =38503a(14) =49141a(15) =60031a(16) =64261a(17) =73153a(18) =79003a(19) =88831a(20) =104653a(21) =108811a(22) =114481a(23) =126253a(24) =146611a(25) =158203a(26) =171991a(27) =188191a(28) =218791a(29) =226801