A034973 - cp's OEIS frontend

A034973 Number of distinct prime factors in central binomial coefficients C(n, floor(n/2)), the terms of A001405.

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

[0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 13, 13, 12, 12, 12, 12, 12, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 14, 14, 15, 15, 15, 15, 16]

cp's OEIS Frontend

A034973 Number of distinct prime factors in central binomial coefficients C(n, floor(n/2)), the terms of A001405.

Table of values

List of values

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

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

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