A144907 - cp's OEIS frontend

A144907 a(n) = 1 if n is prime, 2 * rad(n) if four divides n and rad(n) otherwise.

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

[1, 1, 1, 4, 1, 6, 1, 4, 3, 10, 1, 12, 1, 14, 15, 4, 1, 6, 1, 20, 21, 22, 1, 12, 5, 26, 3, 28, 1, 30, 1, 4, 33, 34, 35, 12, 1, 38, 39, 20, 1, 42, 1, 44, 15, 46, 1, 12, 7, 10, 51, 52, 1, 6, 55, 28, 57, 58, 1, 60, 1, 62, 21, 4, 65, 66, 1, 68, 69, 70, 1, 12, 1, 74, 15, 76, 77, 78, 1, 20, 3, 82]

cp's OEIS Frontend

A144907 a(n) = 1 if n is prime, 2 * rad(n) if four divides n and rad(n) otherwise.

Table of values

List of values

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

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

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