A326147 - cp's OEIS frontend

A326147 a(n) = gcd(n-A020639(n), sigma(n)-A020639(n)-n), where A020639 gives the smallest prime factor of n, and sigma is the sum of divisors of n.

n	a(n)
1	1
2	1
3	2
4	1
5	4
6	4
7	6
8	1
9	1
10	2
11	10
12	2
13	12
14	4
15	6
16	1
17	16
18	1
19	18
20	2
21	2
22	4
23	22
24	2
25	1
26	2
27	2
28	26
29	28
30	4
31	30
32	1
33	6
34	2
35	2
36	1
37	36
38	4
39	2
40	2
41	40
42	4
43	42
44	2
45	6
46	4
47	46
48	2
49	1
50	1
51	6
52	2
53	52
54	4
55	2
56	2
57	2
58	2
59	58
60	2
61	60
62	4
63	2
64	1
65	2
66	4
67	66
68	2
69	6
70	4
71	70
72	1
73	72
74	2
75	2
76	2
77	2
78	4
79	78
80	26
81	1
82	2
83	82
84	2
85	2
86	4
87	6
88	2
89	88
90	2
91	14
92	2
93	2
94	4
95	10
96	2
97	96
98	1
99	6
100	1
101	100
102	4
103	102
104	2
105	6

[1, 1, 2, 1, 4, 4, 6, 1, 1, 2, 10, 2, 12, 4, 6, 1, 16, 1, 18, 2, 2, 4, 22, 2, 1, 2, 2, 26, 28, 4, 30, 1, 6, 2, 2, 1, 36, 4, 2, 2, 40, 4, 42, 2, 6, 4, 46, 2, 1, 1, 6, 2, 52, 4, 2, 2, 2, 2, 58, 2, 60, 4, 2, 1, 2, 4, 66, 2, 6, 4, 70, 1, 72, 2, 2, 2, 2, 4, 78, 26, 1, 2, 82, 2, 2, 4, 6, 2, 88, 2, 14, 2, 2, 4, 10, 2, 96, 1, 6, 1, 100, 4, 102, 2, 6]

cp's OEIS Frontend

A326147 a(n) = gcd(n-A020639(n), sigma(n)-A020639(n)-n), where A020639 gives the smallest prime factor of n, and sigma is the sum of divisors of n.

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	1
5	4
6	4
7	6
8	1
9	1
10	2
11	10
12	2
13	12
14	4
15	6
16	1
17	16
18	1
19	18
20	2
21	2
22	4
23	22
24	2
25	1
26	2
27	2
28	26
29	28
30	4
31	30
32	1
33	6
34	2
35	2
36	1
37	36
38	4
39	2
40	2
41	40
42	4
43	42
44	2
45	6
46	4
47	46
48	2
49	1
50	1
51	6
52	2
53	52
54	4
55	2
56	2
57	2
58	2
59	58
60	2
61	60
62	4
63	2
64	1
65	2
66	4
67	66
68	2
69	6
70	4
71	70
72	1
73	72
74	2
75	2
76	2
77	2
78	4
79	78
80	26
81	1
82	2
83	82
84	2
85	2
86	4
87	6
88	2
89	88
90	2
91	14
92	2
93	2
94	4
95	10
96	2
97	96
98	1
99	6
100	1
101	100
102	4
103	102
104	2
105	6

n	a(n)
1	1
2	1
3	2
4	1
5	4
6	4
7	6
8	1
9	1
10	2
11	10
12	2
13	12
14	4
15	6
16	1
17	16
18	1
19	18
20	2
21	2
22	4
23	22
24	2
25	1
26	2
27	2
28	26
29	28
30	4
31	30
32	1
33	6
34	2
35	2
36	1
37	36
38	4
39	2
40	2
41	40
42	4
43	42
44	2
45	6
46	4
47	46
48	2
49	1
50	1
51	6
52	2
53	52
54	4
55	2
56	2
57	2
58	2
59	58
60	2
61	60
62	4
63	2
64	1
65	2
66	4
67	66
68	2
69	6
70	4
71	70
72	1
73	72
74	2
75	2
76	2
77	2
78	4
79	78
80	26
81	1
82	2
83	82
84	2
85	2
86	4
87	6
88	2
89	88
90	2
91	14
92	2
93	2
94	4
95	10
96	2
97	96
98	1
99	6
100	1
101	100
102	4
103	102
104	2
105	6

n	a(n)
1	1
2	1
3	2
4	1
5	4
6	4
7	6
8	1
9	1
10	2
11	10
12	2
13	12
14	4
15	6
16	1
17	16
18	1
19	18
20	2
21	2
22	4
23	22
24	2
25	1
26	2
27	2
28	26
29	28
30	4
31	30
32	1
33	6
34	2
35	2
36	1
37	36
38	4
39	2
40	2
41	40
42	4
43	42
44	2
45	6
46	4
47	46
48	2
49	1
50	1
51	6
52	2
53	52
54	4
55	2
56	2
57	2
58	2
59	58
60	2
61	60
62	4
63	2
64	1
65	2
66	4
67	66
68	2
69	6
70	4
71	70
72	1
73	72
74	2
75	2
76	2
77	2
78	4
79	78
80	26
81	1
82	2
83	82
84	2
85	2
86	4
87	6
88	2
89	88
90	2
91	14
92	2
93	2
94	4
95	10
96	2
97	96
98	1
99	6
100	1
101	100
102	4
103	102
104	2
105	6