A276039 - OEIS

A276039 as a simple table

n	a(n)
1	1
2	7
3	11
4	17
5	71
6	77
7	111
8	117
9	171
10	177
11	711
12	717
13	771
14	777
15	1111
16	1117
17	1171
18	1177
19	1711
20	1717
21	1771
22	1777
23	7111
24	7117
25	7171
26	7177
27	7711
28	7717
29	7771
30	7777
31	11111
32	11117
33	11171
34	11177
35	11711
36	11717
37	11771
38	11777
39	17111
40	17117
41	17171
42	17177
43	17711
44	17717
45	17771
46	17777

[1,7,11,17,71,77,111,117,171,177,711,717,771,777, 1111,1117,1171,1177,1711,1717,1771,1777,7111,7117, 7171,7177,7711,7717,7771,7777,11111,11117,11171, 11177,11711,11717,11771,11777,17111,17117,17171, 17177,17711,17717,17771,17777]