A033108 - cp's OEIS frontend

A033108 Number of 7's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n.

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	1
8	1
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	3
17	4
18	5
19	6
20	7
21	8
22	9
23	11
24	12
25	14
26	15
27	17
28	18
29	20
30	21
31	24
32	25
33	27
34	29
35	31
36	32
37	35
38	36
39	39
40	41
41	43
42	44
43	48
44	49
45	51
46	53
47	57
48	58
49	61
50	62
51	65
52	68
53	70
54	71
55	76
56	78
57	82
58	85
59	89
60	91
61	96
62	99
63	105
64	108
65	111
66	113
67	120

[0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 15, 17, 18, 20, 21, 24, 25, 27, 29, 31, 32, 35, 36, 39, 41, 43, 44, 48, 49, 51, 53, 57, 58, 61, 62, 65, 68, 70, 71, 76, 78, 82, 85, 89, 91, 96, 99, 105, 108, 111, 113, 120]

cp's OEIS Frontend

A033108 Number of 7's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	1
8	1
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	3
17	4
18	5
19	6
20	7
21	8
22	9
23	11
24	12
25	14
26	15
27	17
28	18
29	20
30	21
31	24
32	25
33	27
34	29
35	31
36	32
37	35
38	36
39	39
40	41
41	43
42	44
43	48
44	49
45	51
46	53
47	57
48	58
49	61
50	62
51	65
52	68
53	70
54	71
55	76
56	78
57	82
58	85
59	89
60	91
61	96
62	99
63	105
64	108
65	111
66	113
67	120

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	1
8	1
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	3
17	4
18	5
19	6
20	7
21	8
22	9
23	11
24	12
25	14
26	15
27	17
28	18
29	20
30	21
31	24
32	25
33	27
34	29
35	31
36	32
37	35
38	36
39	39
40	41
41	43
42	44
43	48
44	49
45	51
46	53
47	57
48	58
49	61
50	62
51	65
52	68
53	70
54	71
55	76
56	78
57	82
58	85
59	89
60	91
61	96
62	99
63	105
64	108
65	111
66	113
67	120

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	1
8	1
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	3
17	4
18	5
19	6
20	7
21	8
22	9
23	11
24	12
25	14
26	15
27	17
28	18
29	20
30	21
31	24
32	25
33	27
34	29
35	31
36	32
37	35
38	36
39	39
40	41
41	43
42	44
43	48
44	49
45	51
46	53
47	57
48	58
49	61
50	62
51	65
52	68
53	70
54	71
55	76
56	78
57	82
58	85
59	89
60	91
61	96
62	99
63	105
64	108
65	111
66	113
67	120