A018830 Numbers n such that n is a substring of its square in base 6 (written in base 10).

0, 1, 3, 4, 6, 9, 18, 24, 28, 36, 54, 81, 108, 136, 144, 168, 216, 324, 486, 648, 816, 864, 1008, 1216, 1296, 1944, 2916, 3888, 4896, 5184, 6048, 6458, 6561, 7296, 7776, 8451, 11664, 16768, 17496, 22779, 23328, 23985, 29376, 29889, 31104, 34299, 34549, 36288