A305927 - cp's OEIS frontend

A305927 Irregular table: row n >= 0 lists all k >= 0 such that the decimal representation of 7^k has n digits '0' (conjectured).

n	a(n)
0	0
1	1
2	2
3	3
4	6
5	7
6	10
7	11
8	19
9	35
10	4
11	5
12	8
13	12
14	14
15	15
16	18
17	27
18	43
19	47
20	51
21	9
22	16
23	17
24	20
25	24
26	26
27	28
28	29
29	34
30	38
31	52
32	93
33	13
34	21
35	22
36	23
37	30
38	31
39	36
40	37
41	42
42	44
43	46
44	49
45	58
46	25
47	32
48	33
49	50
50	53
51	54
52	59
53	66
54	122
55	55
56	56
57	57
58	61
59	62
60	64
61	67
62	72
63	73
64	74
65	39
66	40
67	48
68	60
69	71
70	77
71	79
72	96
73	108

[0, 1, 2, 3, 6, 7, 10, 11, 19, 35, 4, 5, 8, 12, 14, 15, 18, 27, 43, 47, 51, 9, 16, 17, 20, 24, 26, 28, 29, 34, 38, 52, 93, 13, 21, 22, 23, 30, 31, 36, 37, 42, 44, 46, 49, 58, 25, 32, 33, 50, 53, 54, 59, 66, 122, 55, 56, 57, 61, 62, 64, 67, 72, 73, 74, 39, 40, 48, 60, 71, 77, 79, 96, 108]

cp's OEIS Frontend

A305927 Irregular table: row n >= 0 lists all k >= 0 such that the decimal representation of 7^k has n digits '0' (conjectured).

Table of values

List of values

n	a(n)
0	0
1	1
2	2
3	3
4	6
5	7
6	10
7	11
8	19
9	35
10	4
11	5
12	8
13	12
14	14
15	15
16	18
17	27
18	43
19	47
20	51
21	9
22	16
23	17
24	20
25	24
26	26
27	28
28	29
29	34
30	38
31	52
32	93
33	13
34	21
35	22
36	23
37	30
38	31
39	36
40	37
41	42
42	44
43	46
44	49
45	58
46	25
47	32
48	33
49	50
50	53
51	54
52	59
53	66
54	122
55	55
56	56
57	57
58	61
59	62
60	64
61	67
62	72
63	73
64	74
65	39
66	40
67	48
68	60
69	71
70	77
71	79
72	96
73	108

n	a(n)
0	0
1	1
2	2
3	3
4	6
5	7
6	10
7	11
8	19
9	35
10	4
11	5
12	8
13	12
14	14
15	15
16	18
17	27
18	43
19	47
20	51
21	9
22	16
23	17
24	20
25	24
26	26
27	28
28	29
29	34
30	38
31	52
32	93
33	13
34	21
35	22
36	23
37	30
38	31
39	36
40	37
41	42
42	44
43	46
44	49
45	58
46	25
47	32
48	33
49	50
50	53
51	54
52	59
53	66
54	122
55	55
56	56
57	57
58	61
59	62
60	64
61	67
62	72
63	73
64	74
65	39
66	40
67	48
68	60
69	71
70	77
71	79
72	96
73	108

n	a(n)
0	0
1	1
2	2
3	3
4	6
5	7
6	10
7	11
8	19
9	35
10	4
11	5
12	8
13	12
14	14
15	15
16	18
17	27
18	43
19	47
20	51
21	9
22	16
23	17
24	20
25	24
26	26
27	28
28	29
29	34
30	38
31	52
32	93
33	13
34	21
35	22
36	23
37	30
38	31
39	36
40	37
41	42
42	44
43	46
44	49
45	58
46	25
47	32
48	33
49	50
50	53
51	54
52	59
53	66
54	122
55	55
56	56
57	57
58	61
59	62
60	64
61	67
62	72
63	73
64	74
65	39
66	40
67	48
68	60
69	71
70	77
71	79
72	96
73	108