A020657 - OEIS

A020657 as a simple table

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	7
8	8
9	9
10	10
11	11
12	12
13	14
14	15
15	16
16	17
17	18
18	19
19	21
20	22
21	23
22	24
23	25
24	26
25	28
26	29
27	30
28	31
29	32
30	33
31	35
32	36
33	37
34	38
35	39
36	40
37	49
38	50
39	51
40	52
41	53
42	54
43	56
44	57
45	58
46	59
47	60
48	61
49	63
50	64
51	65
52	66
53	67
54	68
55	70
56	71
57	72
58	73
59	74
60	75
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85

[0,1,2,3,4,5,7,8,9,10,11,12,14,15,16,17,18,19,21, 22,23,24,25,26,28,29,30,31,32,33,35,36,37,38,39, 40,49,50,51,52,53,54,56,57,58,59,60,61,63,64,65, 66,67,68,70,71,72,73,74,75,77,78,79,80,81,82,84, 85]

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	7
8	8
9	9
10	10
11	11
12	12
13	14
14	15
15	16
16	17
17	18
18	19
19	21
20	22
21	23
22	24
23	25
24	26
25	28
26	29
27	30
28	31
29	32
30	33
31	35
32	36
33	37
34	38
35	39
36	40
37	49
38	50
39	51
40	52
41	53
42	54
43	56
44	57
45	58
46	59
47	60
48	61
49	63
50	64
51	65
52	66
53	67
54	68
55	70
56	71
57	72
58	73
59	74
60	75
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	7
8	8
9	9
10	10
11	11
12	12
13	14
14	15
15	16
16	17
17	18
18	19
19	21
20	22
21	23
22	24
23	25
24	26
25	28
26	29
27	30
28	31
29	32
30	33
31	35
32	36
33	37
34	38
35	39
36	40
37	49
38	50
39	51
40	52
41	53
42	54
43	56
44	57
45	58
46	59
47	60
48	61
49	63
50	64
51	65
52	66
53	67
54	68
55	70
56	71
57	72
58	73
59	74
60	75
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	7
8	8
9	9
10	10
11	11
12	12
13	14
14	15
15	16
16	17
17	18
18	19
19	21
20	22
21	23
22	24
23	25
24	26
25	28
26	29
27	30
28	31
29	32
30	33
31	35
32	36
33	37
34	38
35	39
36	40
37	49
38	50
39	51
40	52
41	53
42	54
43	56
44	57
45	58
46	59
47	60
48	61
49	63
50	64
51	65
52	66
53	67
54	68
55	70
56	71
57	72
58	73
59	74
60	75
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85