(By Jakob Lesage): "Are any numerals above 5 formed with 5 as a base? For example, 6 = 5+1, 7 = 5+2, 8 = 5+3, 9 = 5+4, 11 = 5+5+1, etc.? One example of this is enough for a 1, except if it can be derived from an already existing non-quinary system (e.g. if 10 = 5x2, but other numerals are also formed by doubling, e.g. 4 = 2x2 and 6 = 3x2, this does not count)."