A056173 - cp's OEIS frontend

A056173 Number of unitary prime divisors of central binomial coefficient C(n, floor(n/2)) (A001405).

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	1
7	2
8	3
9	2
10	1
11	4
12	3
13	3
14	3
15	3
16	4
17	5
18	4
19	5
20	4
21	5
22	5
23	6
24	5
25	4
26	4
27	3
28	3
29	5
30	5
31	6
32	7
33	7
34	6
35	8
36	7
37	7
38	7
39	9
40	8
41	9
42	9
43	9
44	9
45	6
46	6
47	8
48	7
49	7
50	7
51	7
52	7
53	8
54	8
55	11
56	11
57	12
58	12
59	11
60	11
61	11
62	11
63	10
64	11
65	13
66	12
67	13
68	12
69	12
70	12
71	14
72	13
73	13
74	13
75	13
76	13
77	11
78	11
79	14
80	13
81	12
82	12
83	14
84	14
85	13
86	13
87	13

[0, 1, 1, 2, 2, 1, 2, 3, 2, 1, 4, 3, 3, 3, 3, 4, 5, 4, 5, 4, 5, 5, 6, 5, 4, 4, 3, 3, 5, 5, 6, 7, 7, 6, 8, 7, 7, 7, 9, 8, 9, 9, 9, 9, 6, 6, 8, 7, 7, 7, 7, 7, 8, 8, 11, 11, 12, 12, 11, 11, 11, 11, 10, 11, 13, 12, 13, 12, 12, 12, 14, 13, 13, 13, 13, 13, 11, 11, 14, 13, 12, 12, 14, 14, 13, 13, 13]

cp's OEIS Frontend

A056173 Number of unitary prime divisors of central binomial coefficient C(n, floor(n/2)) (A001405).

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	1
7	2
8	3
9	2
10	1
11	4
12	3
13	3
14	3
15	3
16	4
17	5
18	4
19	5
20	4
21	5
22	5
23	6
24	5
25	4
26	4
27	3
28	3
29	5
30	5
31	6
32	7
33	7
34	6
35	8
36	7
37	7
38	7
39	9
40	8
41	9
42	9
43	9
44	9
45	6
46	6
47	8
48	7
49	7
50	7
51	7
52	7
53	8
54	8
55	11
56	11
57	12
58	12
59	11
60	11
61	11
62	11
63	10
64	11
65	13
66	12
67	13
68	12
69	12
70	12
71	14
72	13
73	13
74	13
75	13
76	13
77	11
78	11
79	14
80	13
81	12
82	12
83	14
84	14
85	13
86	13
87	13

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	1
7	2
8	3
9	2
10	1
11	4
12	3
13	3
14	3
15	3
16	4
17	5
18	4
19	5
20	4
21	5
22	5
23	6
24	5
25	4
26	4
27	3
28	3
29	5
30	5
31	6
32	7
33	7
34	6
35	8
36	7
37	7
38	7
39	9
40	8
41	9
42	9
43	9
44	9
45	6
46	6
47	8
48	7
49	7
50	7
51	7
52	7
53	8
54	8
55	11
56	11
57	12
58	12
59	11
60	11
61	11
62	11
63	10
64	11
65	13
66	12
67	13
68	12
69	12
70	12
71	14
72	13
73	13
74	13
75	13
76	13
77	11
78	11
79	14
80	13
81	12
82	12
83	14
84	14
85	13
86	13
87	13

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	1
7	2
8	3
9	2
10	1
11	4
12	3
13	3
14	3
15	3
16	4
17	5
18	4
19	5
20	4
21	5
22	5
23	6
24	5
25	4
26	4
27	3
28	3
29	5
30	5
31	6
32	7
33	7
34	6
35	8
36	7
37	7
38	7
39	9
40	8
41	9
42	9
43	9
44	9
45	6
46	6
47	8
48	7
49	7
50	7
51	7
52	7
53	8
54	8
55	11
56	11
57	12
58	12
59	11
60	11
61	11
62	11
63	10
64	11
65	13
66	12
67	13
68	12
69	12
70	12
71	14
72	13
73	13
74	13
75	13
76	13
77	11
78	11
79	14
80	13
81	12
82	12
83	14
84	14
85	13
86	13
87	13