A091678 In base 4, numbers n of the form k + reverse(k) for at least one k.

0, 2, 4, 5, 6, 10, 15, 17, 20, 25, 30, 33, 34, 41, 42, 50, 51, 58, 59, 65, 67, 68, 75, 76, 84, 85, 92, 93, 101, 102, 105, 109, 110, 118, 125, 126, 130, 145, 150, 165, 170, 185, 190, 195, 210, 215, 230, 235, 250, 255, 257, 260, 275, 280, 289, 295, 300, 315, 320, 321