A033023 - OEIS

A033023 as a simple table

n	a(n)
1	11
2	22
3	33
4	44
5	55
6	66
7	77
8	88
9	99
10	111
11	222
12	333
13	444
14	555
15	666
16	777
17	888
18	999
19	1100
20	1111
21	1122
22	1133
23	1144
24	1155
25	1166
26	1177
27	1188
28	1199
29	2200
30	2211
31	2222
32	2233
33	2244
34	2255
35	2266
36	2277
37	2288
38	2299
39	3300
40	3311
41	3322
42	3333

[11,22,33,44,55,66,77,88,99,111,222,333,444,555, 666,777,888,999,1100,1111,1122,1133,1144,1155, 1166,1177,1188,1199,2200,2211,2222,2233,2244,2255, 2266,2277,2288,2299,3300,3311,3322,3333]