A366387 - cp's OEIS frontend

A366387 Divide n by its smallest prime factor, then multiply with the index of that same prime; a(1) = 0 by convention.

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

[0, 1, 2, 2, 3, 3, 4, 4, 6, 5, 5, 6, 6, 7, 10, 8, 7, 9, 8, 10, 14, 11, 9, 12, 15, 13, 18, 14, 10, 15, 11, 16, 22, 17, 21, 18, 12, 19, 26, 20, 13, 21, 14, 22, 30, 23, 15, 24, 28, 25, 34, 26, 16, 27, 33, 28, 38, 29, 17, 30, 18, 31, 42, 32, 39, 33, 19, 34, 46, 35, 20, 36, 21, 37, 50, 38, 44, 39, 22, 40, 54, 41, 23, 42, 51]

cp's OEIS Frontend

A366387 Divide n by its smallest prime factor, then multiply with the index of that same prime; a(1) = 0 by convention.

Table of values

List of values

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

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

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