A090618 - cp's OEIS frontend

A090618 Highest power of 9 dividing n!.

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	1
7	1
8	1
9	2
10	2
11	2
12	2
13	2
14	2
15	3
16	3
17	3
18	4
19	4
20	4
21	4
22	4
23	4
24	5
25	5
26	5
27	6
28	6
29	6
30	7
31	7
32	7
33	7
34	7
35	7
36	8
37	8
38	8
39	9
40	9
41	9
42	9
43	9
44	9
45	10
46	10
47	10
48	11
49	11
50	11
51	11
52	11
53	11
54	13
55	13
56	13
57	13
58	13
59	13
60	14
61	14
62	14
63	15
64	15
65	15
66	15
67	15
68	15
69	16
70	16
71	16
72	17
73	17
74	17
75	17
76	17
77	17
78	18
79	18
80	18
81	20
82	20
83	20
84	20

[0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 11, 11, 11, 11, 11, 11, 13, 13, 13, 13, 13, 13, 14, 14, 14, 15, 15, 15, 15, 15, 15, 16, 16, 16, 17, 17, 17, 17, 17, 17, 18, 18, 18, 20, 20, 20, 20]

cp's OEIS Frontend

A090618 Highest power of 9 dividing n!.

Table of values

List of values

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	1
7	1
8	1
9	2
10	2
11	2
12	2
13	2
14	2
15	3
16	3
17	3
18	4
19	4
20	4
21	4
22	4
23	4
24	5
25	5
26	5
27	6
28	6
29	6
30	7
31	7
32	7
33	7
34	7
35	7
36	8
37	8
38	8
39	9
40	9
41	9
42	9
43	9
44	9
45	10
46	10
47	10
48	11
49	11
50	11
51	11
52	11
53	11
54	13
55	13
56	13
57	13
58	13
59	13
60	14
61	14
62	14
63	15
64	15
65	15
66	15
67	15
68	15
69	16
70	16
71	16
72	17
73	17
74	17
75	17
76	17
77	17
78	18
79	18
80	18
81	20
82	20
83	20
84	20

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	1
7	1
8	1
9	2
10	2
11	2
12	2
13	2
14	2
15	3
16	3
17	3
18	4
19	4
20	4
21	4
22	4
23	4
24	5
25	5
26	5
27	6
28	6
29	6
30	7
31	7
32	7
33	7
34	7
35	7
36	8
37	8
38	8
39	9
40	9
41	9
42	9
43	9
44	9
45	10
46	10
47	10
48	11
49	11
50	11
51	11
52	11
53	11
54	13
55	13
56	13
57	13
58	13
59	13
60	14
61	14
62	14
63	15
64	15
65	15
66	15
67	15
68	15
69	16
70	16
71	16
72	17
73	17
74	17
75	17
76	17
77	17
78	18
79	18
80	18
81	20
82	20
83	20
84	20

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	1
7	1
8	1
9	2
10	2
11	2
12	2
13	2
14	2
15	3
16	3
17	3
18	4
19	4
20	4
21	4
22	4
23	4
24	5
25	5
26	5
27	6
28	6
29	6
30	7
31	7
32	7
33	7
34	7
35	7
36	8
37	8
38	8
39	9
40	9
41	9
42	9
43	9
44	9
45	10
46	10
47	10
48	11
49	11
50	11
51	11
52	11
53	11
54	13
55	13
56	13
57	13
58	13
59	13
60	14
61	14
62	14
63	15
64	15
65	15
66	15
67	15
68	15
69	16
70	16
71	16
72	17
73	17
74	17
75	17
76	17
77	17
78	18
79	18
80	18
81	20
82	20
83	20
84	20