A081388 - cp's OEIS frontend

A081388 Number of unitary prime divisors of the n-th Catalan number.

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

[0, 1, 1, 2, 3, 2, 3, 4, 4, 3, 5, 4, 3, 4, 5, 6, 8, 6, 9, 8, 8, 8, 7, 7, 6, 7, 9, 10, 10, 10, 11, 11, 12, 12, 13, 12, 12, 11, 13, 12, 13, 13, 12, 14, 14, 13, 15, 14, 15, 15, 15, 15, 18, 17, 17, 17, 17, 18, 17, 18, 17, 18, 18, 19, 21, 20, 22, 19, 19, 19, 21, 19, 19, 20, 20, 23, 23, 22]

cp's OEIS Frontend

A081388 Number of unitary prime divisors of the n-th Catalan number.

Table of values

List of values

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

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

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