\begin{definition}[Definition:Lucky Number/Sequence]
The sequence of lucky numbers begins:
:$1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79, 87, 93, 99, \ldots$
{{OEIS|A000959}}
\end{definition}