A173557 - cp's OEIS frontend

A173557 a(n) = Product_{primes p dividing n} (p-1).

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

[1, 1, 2, 1, 4, 2, 6, 1, 2, 4, 10, 2, 12, 6, 8, 1, 16, 2, 18, 4, 12, 10, 22, 2, 4, 12, 2, 6, 28, 8, 30, 1, 20, 16, 24, 2, 36, 18, 24, 4, 40, 12, 42, 10, 8, 22, 46, 2, 6, 4, 32, 12, 52, 2, 40, 6, 36, 28, 58, 8, 60, 30, 12, 1, 48, 20, 66, 16, 44, 24, 70, 2, 72, 36]

cp's OEIS Frontend

A173557 a(n) = Product_{primes p dividing n} (p-1).

Table of values

List of values

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

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

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