Definition:Kaprekar Number/Sequence

Definition
The sequence of Kaprekar numbers begins:
 * $1, 9, 45, 55, 99, 297, 703, 999, 2223, 2728, 4879, 4950, 5050, 5292, 7272, 7777, 9999, 17344, \ldots$

Some sources do not include such numbers as $4879$ and $5292$:
 * $1, 9, 45, 55, 99, 297, 703, 999, 2223, 2728, 4950, 5050, 7272, 7777, 9999, 17344, \ldots$

where the $2$nd of the $2$ parts begins with one or more leading zeroes:
 * $4879^2 = 23 \, 804 \, 641 \to 238 + 04641 = 4879$
 * $5292^2 = 28 \, 005 \, 264 \to 28 + 005264 = 5292$