A056812 - cp's OEIS frontend

A056812 Number of unitary prime factors of lcm[1..n], i.e., primes in LCM with exponent 1.

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

[0, 1, 2, 1, 2, 2, 3, 3, 2, 2, 3, 3, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 11, 11, 11, 11, 12, 12, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 19]

cp's OEIS Frontend

A056812 Number of unitary prime factors of lcm[1..n], i.e., primes in LCM with exponent 1.

Table of values

List of values

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

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

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