A088535 n representable as x^2+xy+y^2 and such that 3 divides sigma(n).

49, 147, 169, 196, 361, 441, 507, 588, 637, 676, 784, 931, 961, 1083, 1183, 1225, 1323, 1369, 1444, 1519, 1521, 1764, 1813, 1849, 1911, 2028, 2107, 2352, 2527, 2548, 2704, 2793, 2883, 2989, 3136, 3211, 3249, 3283, 3549, 3577, 3675, 3721, 3724, 3844, 3871