18 Apr
2012
18 Apr
'12
9:09 a.m.
Suppose the positive integers n and n^3 both have all digits odd. Such numbers include 1, 11, 15, 33, 39, 71, 91, 173, 175, 179, 335, 3337, 5597, 7353. Is this list complete? This sequence is http://oeis.org/A085597 in OEIS. But there is no key word indicating that it is a finite sequence. Is this known to be a finite sequence?