A144775 - cp's OEIS frontend

A144775 Define f(n) = 2 * rad(n) if four divides n and rad(n) otherwise: then a(n) = 0 for composite n where f(n) is not less than n and otherwise equals the number of positive integers k less than n for which f(k) < f(n).

n	a(n)
1	0
2	1
3	2
4	0
5	4
6	0
7	6
8	3
9	2
10	0
11	10
12	0
13	12
14	0
15	0
16	4
17	16
18	8
19	18
20	0
21	0
22	0
23	22
24	13
25	7
26	0
27	2
28	0
29	28
30	0
31	30
32	5
33	0
34	0
35	0
36	16
37	36
38	0
39	0
40	24
41	40
42	0
43	42
44	0
45	21
46	0
47	46
48	16
49	13
50	15
51	0
52	0
53	52
54	11
55	0
56	35
57	0
58	0
59	58
60	0
61	60
62	0
63	31
64	5
65	0
66	0
67	66
68	0
69	0
70	0
71	70
72	20
73	72
74	0
75	27
76	0
77	0
78	0
79	78
80	32
81	2
82	0
83	82
84	0
85	0
86	0
87	0
88	55

[0, 1, 2, 0, 4, 0, 6, 3, 2, 0, 10, 0, 12, 0, 0, 4, 16, 8, 18, 0, 0, 0, 22, 13, 7, 0, 2, 0, 28, 0, 30, 5, 0, 0, 0, 16, 36, 0, 0, 24, 40, 0, 42, 0, 21, 0, 46, 16, 13, 15, 0, 0, 52, 11, 0, 35, 0, 0, 58, 0, 60, 0, 31, 5, 0, 0, 66, 0, 0, 0, 70, 20, 72, 0, 27, 0, 0, 0, 78, 32, 2, 0, 82, 0, 0, 0, 0, 55]

cp's OEIS Frontend

A144775 Define f(n) = 2 * rad(n) if four divides n and rad(n) otherwise: then a(n) = 0 for composite n where f(n) is not less than n and otherwise equals the number of positive integers k less than n for which f(k) < f(n).

Table of values

List of values

n	a(n)
1	0
2	1
3	2
4	0
5	4
6	0
7	6
8	3
9	2
10	0
11	10
12	0
13	12
14	0
15	0
16	4
17	16
18	8
19	18
20	0
21	0
22	0
23	22
24	13
25	7
26	0
27	2
28	0
29	28
30	0
31	30
32	5
33	0
34	0
35	0
36	16
37	36
38	0
39	0
40	24
41	40
42	0
43	42
44	0
45	21
46	0
47	46
48	16
49	13
50	15
51	0
52	0
53	52
54	11
55	0
56	35
57	0
58	0
59	58
60	0
61	60
62	0
63	31
64	5
65	0
66	0
67	66
68	0
69	0
70	0
71	70
72	20
73	72
74	0
75	27
76	0
77	0
78	0
79	78
80	32
81	2
82	0
83	82
84	0
85	0
86	0
87	0
88	55

n	a(n)
1	0
2	1
3	2
4	0
5	4
6	0
7	6
8	3
9	2
10	0
11	10
12	0
13	12
14	0
15	0
16	4
17	16
18	8
19	18
20	0
21	0
22	0
23	22
24	13
25	7
26	0
27	2
28	0
29	28
30	0
31	30
32	5
33	0
34	0
35	0
36	16
37	36
38	0
39	0
40	24
41	40
42	0
43	42
44	0
45	21
46	0
47	46
48	16
49	13
50	15
51	0
52	0
53	52
54	11
55	0
56	35
57	0
58	0
59	58
60	0
61	60
62	0
63	31
64	5
65	0
66	0
67	66
68	0
69	0
70	0
71	70
72	20
73	72
74	0
75	27
76	0
77	0
78	0
79	78
80	32
81	2
82	0
83	82
84	0
85	0
86	0
87	0
88	55

n	a(n)
1	0
2	1
3	2
4	0
5	4
6	0
7	6
8	3
9	2
10	0
11	10
12	0
13	12
14	0
15	0
16	4
17	16
18	8
19	18
20	0
21	0
22	0
23	22
24	13
25	7
26	0
27	2
28	0
29	28
30	0
31	30
32	5
33	0
34	0
35	0
36	16
37	36
38	0
39	0
40	24
41	40
42	0
43	42
44	0
45	21
46	0
47	46
48	16
49	13
50	15
51	0
52	0
53	52
54	11
55	0
56	35
57	0
58	0
59	58
60	0
61	60
62	0
63	31
64	5
65	0
66	0
67	66
68	0
69	0
70	0
71	70
72	20
73	72
74	0
75	27
76	0
77	0
78	0
79	78
80	32
81	2
82	0
83	82
84	0
85	0
86	0
87	0
88	55