A340071 - cp's OEIS frontend

A340071 a(n) = gcd(A003961(n)-1, phi(A003961(n))), where A003961 shifts the prime factorization of n one step towards larger primes.

n	a(n)
1	1
2	2
3	4
4	2
5	6
6	2
7	10
8	2
9	4
10	4
11	12
12	4
13	16
14	4
15	2
16	2
17	18
18	2
19	22
20	2
21	2
22	2
23	28
24	2
25	6
26	2
27	4
28	2
29	30
30	8
31	36
32	2
33	16
34	4
35	4
36	8
37	40
38	4
39	4
40	4
41	42
42	4
43	46
44	4
45	6
46	2
47	52
48	4
49	10
50	2
51	2
52	8
53	58
54	2
55	18
56	4
57	2
58	4
59	60
60	2
61	66
62	2
63	2
64	2
65	2
66	2
67	70
68	2
69	16
70	10
71	72
72	2
73	78
74	2
75	4
76	2
77	2
78	2
79	82
80	2
81	4
82	4
83	88
84	2
85	12
86	4
87	2
88	2
89	96
90	4
91	2
92	4
93	8
94	2
95	4
96	2
97	100

[1, 2, 4, 2, 6, 2, 10, 2, 4, 4, 12, 4, 16, 4, 2, 2, 18, 2, 22, 2, 2, 2, 28, 2, 6, 2, 4, 2, 30, 8, 36, 2, 16, 4, 4, 8, 40, 4, 4, 4, 42, 4, 46, 4, 6, 2, 52, 4, 10, 2, 2, 8, 58, 2, 18, 4, 2, 4, 60, 2, 66, 2, 2, 2, 2, 2, 70, 2, 16, 10, 72, 2, 78, 2, 4, 2, 2, 2, 82, 2, 4, 4, 88, 2, 12, 4, 2, 2, 96, 4, 2, 4, 8, 2, 4, 2, 100]

cp's OEIS Frontend

A340071 a(n) = gcd(A003961(n)-1, phi(A003961(n))), where A003961 shifts the prime factorization of n one step towards larger primes.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	2
5	6
6	2
7	10
8	2
9	4
10	4
11	12
12	4
13	16
14	4
15	2
16	2
17	18
18	2
19	22
20	2
21	2
22	2
23	28
24	2
25	6
26	2
27	4
28	2
29	30
30	8
31	36
32	2
33	16
34	4
35	4
36	8
37	40
38	4
39	4
40	4
41	42
42	4
43	46
44	4
45	6
46	2
47	52
48	4
49	10
50	2
51	2
52	8
53	58
54	2
55	18
56	4
57	2
58	4
59	60
60	2
61	66
62	2
63	2
64	2
65	2
66	2
67	70
68	2
69	16
70	10
71	72
72	2
73	78
74	2
75	4
76	2
77	2
78	2
79	82
80	2
81	4
82	4
83	88
84	2
85	12
86	4
87	2
88	2
89	96
90	4
91	2
92	4
93	8
94	2
95	4
96	2
97	100

n	a(n)
1	1
2	2
3	4
4	2
5	6
6	2
7	10
8	2
9	4
10	4
11	12
12	4
13	16
14	4
15	2
16	2
17	18
18	2
19	22
20	2
21	2
22	2
23	28
24	2
25	6
26	2
27	4
28	2
29	30
30	8
31	36
32	2
33	16
34	4
35	4
36	8
37	40
38	4
39	4
40	4
41	42
42	4
43	46
44	4
45	6
46	2
47	52
48	4
49	10
50	2
51	2
52	8
53	58
54	2
55	18
56	4
57	2
58	4
59	60
60	2
61	66
62	2
63	2
64	2
65	2
66	2
67	70
68	2
69	16
70	10
71	72
72	2
73	78
74	2
75	4
76	2
77	2
78	2
79	82
80	2
81	4
82	4
83	88
84	2
85	12
86	4
87	2
88	2
89	96
90	4
91	2
92	4
93	8
94	2
95	4
96	2
97	100

n	a(n)
1	1
2	2
3	4
4	2
5	6
6	2
7	10
8	2
9	4
10	4
11	12
12	4
13	16
14	4
15	2
16	2
17	18
18	2
19	22
20	2
21	2
22	2
23	28
24	2
25	6
26	2
27	4
28	2
29	30
30	8
31	36
32	2
33	16
34	4
35	4
36	8
37	40
38	4
39	4
40	4
41	42
42	4
43	46
44	4
45	6
46	2
47	52
48	4
49	10
50	2
51	2
52	8
53	58
54	2
55	18
56	4
57	2
58	4
59	60
60	2
61	66
62	2
63	2
64	2
65	2
66	2
67	70
68	2
69	16
70	10
71	72
72	2
73	78
74	2
75	4
76	2
77	2
78	2
79	82
80	2
81	4
82	4
83	88
84	2
85	12
86	4
87	2
88	2
89	96
90	4
91	2
92	4
93	8
94	2
95	4
96	2
97	100