And how many such numbers do you think there are?
Once you get over 50, there aren't any: because all the 2 * i values have at least one more digit that the original number.
50 * 2 == 100
And below 50
i 2i palendrome(i)
1, 2, 1
2, 4, 2
3, 6, 3
4, 8, 4
5, 10, 5
6, 12, 6
7, 14, 7
8, 16, 8
9, 18, 9
10, 20, 1
11, 22, 11
12, 24, 21
13, 26, 31
14, 28, 41
15, 30, 51
16, 32, 61
17, 34, 71
18, 36, 81
19, 38, 91
20, 40, 2
21, 42, 12
22, 44, 22
23, 46, 32
24, 48, 42
25, 50, 52
26, 52, 62
27, 54, 72
28, 56, 82
29, 58, 92
30, 60, 3
31, 62, 13
32, 64, 23
33, 66, 33
34, 68, 43
35, 70, 53
36, 72, 63
37, 74, 73
38, 76, 83
39, 78, 93
40, 80, 4
41, 82, 14
42, 84, 24
43, 86, 34
44, 88, 44
45, 90, 54
46, 92, 64
47, 94, 74
48, 96, 84
49, 98, 94
And there are no values in that list which pass your criteria either...
So you code is doing what it should: not showing anything!