A284964 - OEIS

A284964 as a simple table

n	a(n)
1	3
2	9
3	33
4	39
5	93
6	99
7	333
8	339
9	393
10	399
11	933
12	939
13	993
14	999
15	3333
16	3339
17	3393
18	3399
19	3933
20	3939
21	3993
22	3999
23	9333
24	9339
25	9393
26	9399
27	9933
28	9939
29	9993
30	9999
31	33333
32	33339
33	33393
34	33399
35	33933
36	33939
37	33993
38	33999
39	39333
40	39339
41	39393
42	39399
43	39933
44	39939

[3,9,33,39,93,99,333,339,393,399,933,939,993,999, 3333,3339,3393,3399,3933,3939,3993,3999,9333,9339, 9393,9399,9933,9939,9993,9999,33333,33339,33393, 33399,33933,33939,33993,33999,39333,39339,39393, 39399,39933,39939]