Palindromic Smith Number

Sequence
The sequence of palindromic Smith numbers begins:
 * $4, 22, 121, 202, 454, 535, 636, 666, 1111, 1881, 3663, 7227, 7447, 9229, 10 \, 201, 17 \, 271, 22 \, 522, 24 \, 142, \ldots$