A051243 Base 3 numbers d(1)...d(j) such that d(i)=d(j+1-i) for all but 2 i.

27, 29, 31, 34, 37, 39, 41, 43, 46, 49, 51, 53, 54, 55, 59, 62, 65, 66, 67, 71, 74, 77, 78, 79, 246, 248, 249, 251, 252, 254, 256, 259, 261, 263, 265, 268, 270, 272, 274, 277, 282, 284, 285, 287, 288, 290, 292, 295, 297, 299, 301, 304, 306, 308