Triangular numbers composed of digits {0,3,9}.

Terms

a(0) =3a(1) =300a(2) =903a(3) =990a(4) =3003a(5) =33930a(6) =39903a(7) =339900a(8) =930930a(9) =39033030a(10) =990903903a(11) =3909003990a(12) =3993990000a(13) =33003300903a(14) =39999939903a(15) =90993993300