A354190 - cp's OEIS frontend

A354190 a(n) = phi(A267099(sigma(n))), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes.

n	a(n)
1	1
2	4
3	2
4	12
5	4
6	8
7	4
8	8
9	6
10	20
11	8
12	24
13	12
14	16
15	16
16	40
17	20
18	24
19	4
20	48
21	16
22	40
23	16
24	16
25	40
26	48
27	8
28	48
29	8
30	80
31	16
32	240
33	32
34	100
35	32
36	72
37	28
38	16
39	48
40	40
41	48
42	64
43	32
44	96
45	24
46	80
47	32
48	80
49	112
50	160
51	80
52	156
53	100
54	32
55	80
56	32
57	16
58	40
59	16
60	192
61	40
62	64
63	24
64	148
65	96
66	160
67	20
68	240
69	64
70	160
71	80
72	48
73	22
74	112
75	80
76	48
77	64
78	192
79	16

[1, 4, 2, 12, 4, 8, 4, 8, 6, 20, 8, 24, 12, 16, 16, 40, 20, 24, 4, 48, 16, 40, 16, 16, 40, 48, 8, 48, 8, 80, 16, 240, 32, 100, 32, 72, 28, 16, 48, 40, 48, 64, 32, 96, 24, 80, 32, 80, 112, 160, 80, 156, 100, 32, 80, 32, 16, 40, 16, 192, 40, 64, 24, 148, 96, 160, 20, 240, 64, 160, 80, 48, 22, 112, 80, 48, 64, 192, 16]

cp's OEIS Frontend

A354190 a(n) = phi(A267099(sigma(n))), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes.

Table of values

List of values

n	a(n)
1	1
2	4
3	2
4	12
5	4
6	8
7	4
8	8
9	6
10	20
11	8
12	24
13	12
14	16
15	16
16	40
17	20
18	24
19	4
20	48
21	16
22	40
23	16
24	16
25	40
26	48
27	8
28	48
29	8
30	80
31	16
32	240
33	32
34	100
35	32
36	72
37	28
38	16
39	48
40	40
41	48
42	64
43	32
44	96
45	24
46	80
47	32
48	80
49	112
50	160
51	80
52	156
53	100
54	32
55	80
56	32
57	16
58	40
59	16
60	192
61	40
62	64
63	24
64	148
65	96
66	160
67	20
68	240
69	64
70	160
71	80
72	48
73	22
74	112
75	80
76	48
77	64
78	192
79	16

n	a(n)
1	1
2	4
3	2
4	12
5	4
6	8
7	4
8	8
9	6
10	20
11	8
12	24
13	12
14	16
15	16
16	40
17	20
18	24
19	4
20	48
21	16
22	40
23	16
24	16
25	40
26	48
27	8
28	48
29	8
30	80
31	16
32	240
33	32
34	100
35	32
36	72
37	28
38	16
39	48
40	40
41	48
42	64
43	32
44	96
45	24
46	80
47	32
48	80
49	112
50	160
51	80
52	156
53	100
54	32
55	80
56	32
57	16
58	40
59	16
60	192
61	40
62	64
63	24
64	148
65	96
66	160
67	20
68	240
69	64
70	160
71	80
72	48
73	22
74	112
75	80
76	48
77	64
78	192
79	16

n	a(n)
1	1
2	4
3	2
4	12
5	4
6	8
7	4
8	8
9	6
10	20
11	8
12	24
13	12
14	16
15	16
16	40
17	20
18	24
19	4
20	48
21	16
22	40
23	16
24	16
25	40
26	48
27	8
28	48
29	8
30	80
31	16
32	240
33	32
34	100
35	32
36	72
37	28
38	16
39	48
40	40
41	48
42	64
43	32
44	96
45	24
46	80
47	32
48	80
49	112
50	160
51	80
52	156
53	100
54	32
55	80
56	32
57	16
58	40
59	16
60	192
61	40
62	64
63	24
64	148
65	96
66	160
67	20
68	240
69	64
70	160
71	80
72	48
73	22
74	112
75	80
76	48
77	64
78	192
79	16