Terms of A007504 divisible by 3.

Terms

a(0) =0a(1) =129a(2) =381a(3) =501a(4) =639a(5) =963a(6) =1161a(7) =1371a(8) =1593a(9) =1851a(10) =2127a(11) =2427a(12) =3087a(13) =3447a(14) =3831a(15) =4227a(16) =5589a(17) =6081a(18) =6870a(19) =10191a(20) =10887a(21) =12339a(22) =13101a(23) =13887a(24) =14697a(25) =15537a(26) =16401a(27) =17283a(28) =18189a(29) =19113