A144776 - cp's OEIS frontend

A144776 Define f(n) = 1 if n is prime, 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	0
3	0
4	0
5	0
6	0
7	0
8	5
9	5
10	0
11	0
12	0
13	0
14	0
15	0
16	8
17	0
18	12
19	0
20	0
21	0
22	0
23	0
24	17
25	14
26	0
27	10
28	0
29	0
30	0
31	0
32	14
33	0
34	0
35	0
36	22
37	0
38	0
39	0
40	28
41	0
42	0
43	0
44	0
45	29
46	0
47	0
48	26
49	25
50	26
51	0
52	0
53	0
54	24
55	0
56	42
57	0
58	0
59	0
60	0
61	0
62	0
63	41
64	21
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	35
73	0
74	0
75	42
76	0
77	0
78	0
79	0
80	46
81	23
82	0
83	0
84	0
85	0
86	0
87	0
88	64
89	0
90	58
91	0
92	0
93	0
94	0
95	0

[0, 0, 0, 0, 0, 0, 0, 5, 5, 0, 0, 0, 0, 0, 0, 8, 0, 12, 0, 0, 0, 0, 0, 17, 14, 0, 10, 0, 0, 0, 0, 14, 0, 0, 0, 22, 0, 0, 0, 28, 0, 0, 0, 0, 29, 0, 0, 26, 25, 26, 0, 0, 0, 24, 0, 42, 0, 0, 0, 0, 0, 0, 41, 21, 0, 0, 0, 0, 0, 0, 0, 35, 0, 0, 42, 0, 0, 0, 0, 46, 23, 0, 0, 0, 0, 0, 0, 64, 0, 58, 0, 0, 0, 0, 0]

cp's OEIS Frontend

A144776 Define f(n) = 1 if n is prime, 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	0
3	0
4	0
5	0
6	0
7	0
8	5
9	5
10	0
11	0
12	0
13	0
14	0
15	0
16	8
17	0
18	12
19	0
20	0
21	0
22	0
23	0
24	17
25	14
26	0
27	10
28	0
29	0
30	0
31	0
32	14
33	0
34	0
35	0
36	22
37	0
38	0
39	0
40	28
41	0
42	0
43	0
44	0
45	29
46	0
47	0
48	26
49	25
50	26
51	0
52	0
53	0
54	24
55	0
56	42
57	0
58	0
59	0
60	0
61	0
62	0
63	41
64	21
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	35
73	0
74	0
75	42
76	0
77	0
78	0
79	0
80	46
81	23
82	0
83	0
84	0
85	0
86	0
87	0
88	64
89	0
90	58
91	0
92	0
93	0
94	0
95	0

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	5
9	5
10	0
11	0
12	0
13	0
14	0
15	0
16	8
17	0
18	12
19	0
20	0
21	0
22	0
23	0
24	17
25	14
26	0
27	10
28	0
29	0
30	0
31	0
32	14
33	0
34	0
35	0
36	22
37	0
38	0
39	0
40	28
41	0
42	0
43	0
44	0
45	29
46	0
47	0
48	26
49	25
50	26
51	0
52	0
53	0
54	24
55	0
56	42
57	0
58	0
59	0
60	0
61	0
62	0
63	41
64	21
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	35
73	0
74	0
75	42
76	0
77	0
78	0
79	0
80	46
81	23
82	0
83	0
84	0
85	0
86	0
87	0
88	64
89	0
90	58
91	0
92	0
93	0
94	0
95	0

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	5
9	5
10	0
11	0
12	0
13	0
14	0
15	0
16	8
17	0
18	12
19	0
20	0
21	0
22	0
23	0
24	17
25	14
26	0
27	10
28	0
29	0
30	0
31	0
32	14
33	0
34	0
35	0
36	22
37	0
38	0
39	0
40	28
41	0
42	0
43	0
44	0
45	29
46	0
47	0
48	26
49	25
50	26
51	0
52	0
53	0
54	24
55	0
56	42
57	0
58	0
59	0
60	0
61	0
62	0
63	41
64	21
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	35
73	0
74	0
75	42
76	0
77	0
78	0
79	0
80	46
81	23
82	0
83	0
84	0
85	0
86	0
87	0
88	64
89	0
90	58
91	0
92	0
93	0
94	0
95	0