A340072 - cp's OEIS frontend

A340072 a(n) = phi(x) / gcd(x-1, phi(x)), where x = A003961(n), i.e., n with its prime factorization shifted one step towards larger primes.

n	a(n)
1	1
2	1
3	1
4	3
5	1
6	4
7	1
8	9
9	5
10	3
11	1
12	6
13	1
14	5
15	12
16	27
17	1
18	20
19	1
20	18
21	20
22	12
23	1
24	36
25	7
26	16
27	25
28	30
29	1
30	6
31	1
32	81
33	3
34	9
35	15
36	15
37	1
38	11
39	16
40	27
41	1
42	20
43	1
44	18
45	20
46	28
47	1
48	54
49	11
50	42
51	36
52	12
53	1
54	100
55	4
56	45
57	44
58	15
59	1
60	72
61	1
62	36
63	100
64	243
65	48
66	48
67	1
68	54
69	7
70	12
71	1
72	180
73	1
74	40
75	42
76	66
77	60
78	64
79	1
80	162
81	125
82	21
83	1
84	120
85	9
86	23
87	60
88	108

[1, 1, 1, 3, 1, 4, 1, 9, 5, 3, 1, 6, 1, 5, 12, 27, 1, 20, 1, 18, 20, 12, 1, 36, 7, 16, 25, 30, 1, 6, 1, 81, 3, 9, 15, 15, 1, 11, 16, 27, 1, 20, 1, 18, 20, 28, 1, 54, 11, 42, 36, 12, 1, 100, 4, 45, 44, 15, 1, 72, 1, 36, 100, 243, 48, 48, 1, 54, 7, 12, 1, 180, 1, 40, 42, 66, 60, 64, 1, 162, 125, 21, 1, 120, 9, 23, 60, 108]

cp's OEIS Frontend

A340072 a(n) = phi(x) / gcd(x-1, phi(x)), where x = A003961(n), i.e., n with its prime factorization shifted one step towards larger primes.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	3
5	1
6	4
7	1
8	9
9	5
10	3
11	1
12	6
13	1
14	5
15	12
16	27
17	1
18	20
19	1
20	18
21	20
22	12
23	1
24	36
25	7
26	16
27	25
28	30
29	1
30	6
31	1
32	81
33	3
34	9
35	15
36	15
37	1
38	11
39	16
40	27
41	1
42	20
43	1
44	18
45	20
46	28
47	1
48	54
49	11
50	42
51	36
52	12
53	1
54	100
55	4
56	45
57	44
58	15
59	1
60	72
61	1
62	36
63	100
64	243
65	48
66	48
67	1
68	54
69	7
70	12
71	1
72	180
73	1
74	40
75	42
76	66
77	60
78	64
79	1
80	162
81	125
82	21
83	1
84	120
85	9
86	23
87	60
88	108

n	a(n)
1	1
2	1
3	1
4	3
5	1
6	4
7	1
8	9
9	5
10	3
11	1
12	6
13	1
14	5
15	12
16	27
17	1
18	20
19	1
20	18
21	20
22	12
23	1
24	36
25	7
26	16
27	25
28	30
29	1
30	6
31	1
32	81
33	3
34	9
35	15
36	15
37	1
38	11
39	16
40	27
41	1
42	20
43	1
44	18
45	20
46	28
47	1
48	54
49	11
50	42
51	36
52	12
53	1
54	100
55	4
56	45
57	44
58	15
59	1
60	72
61	1
62	36
63	100
64	243
65	48
66	48
67	1
68	54
69	7
70	12
71	1
72	180
73	1
74	40
75	42
76	66
77	60
78	64
79	1
80	162
81	125
82	21
83	1
84	120
85	9
86	23
87	60
88	108

n	a(n)
1	1
2	1
3	1
4	3
5	1
6	4
7	1
8	9
9	5
10	3
11	1
12	6
13	1
14	5
15	12
16	27
17	1
18	20
19	1
20	18
21	20
22	12
23	1
24	36
25	7
26	16
27	25
28	30
29	1
30	6
31	1
32	81
33	3
34	9
35	15
36	15
37	1
38	11
39	16
40	27
41	1
42	20
43	1
44	18
45	20
46	28
47	1
48	54
49	11
50	42
51	36
52	12
53	1
54	100
55	4
56	45
57	44
58	15
59	1
60	72
61	1
62	36
63	100
64	243
65	48
66	48
67	1
68	54
69	7
70	12
71	1
72	180
73	1
74	40
75	42
76	66
77	60
78	64
79	1
80	162
81	125
82	21
83	1
84	120
85	9
86	23
87	60
88	108