A044165 Numbers n such that string 3,6 occurs in the base 7 representation of n but not of n-1.

27, 76, 125, 174, 189, 223, 272, 321, 370, 419, 468, 517, 532, 566, 615, 664, 713, 762, 811, 860, 875, 909, 958, 1007, 1056, 1105, 1154, 1203, 1218, 1252, 1301, 1323, 1399, 1448, 1497, 1546, 1561, 1595, 1644, 1693, 1742, 1791