A306709 - cp's OEIS frontend

A306709 For n > 1, a(n) = gcd(A001414(n), A167344(n)) where A001414(n) is the sum of primes p dividing n (with repetition) and A167344(n) = b(n) is the totally multiplicative sequence with b(p) = (p-1)*(p+1) = p^2 - 1; a(1) = 0.

n	a(n)
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	3
9	2
10	1
11	1
12	1
13	1
14	9
15	8
16	1
17	1
18	8
19	1
20	9
21	2
22	1
23	1
24	9
25	2
26	3
27	1
28	1
29	1
30	2
31	1
32	1
33	2
34	1
35	12
36	2
37	1
38	3
39	16
40	1
41	1
42	12
43	1
44	15
45	1
46	1
47	1
48	1
49	2
50	12
51	4
52	1
53	1
54	1
55	16
56	1
57	2
58	1
59	1
60	12
61	1
62	3
63	1
64	3
65	18
66	16
67	1
68	3
69	2
70	2
71	1
72	12
73	1
74	3
75	1
76	1
77	18
78	18
79	1
80	1
81	4
82	1
83	1
84	2
85	2
86	9
87	32
88	1
89	1
90	1
91	4
92	27

[0, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 1, 1, 9, 8, 1, 1, 8, 1, 9, 2, 1, 1, 9, 2, 3, 1, 1, 1, 2, 1, 1, 2, 1, 12, 2, 1, 3, 16, 1, 1, 12, 1, 15, 1, 1, 1, 1, 2, 12, 4, 1, 1, 1, 16, 1, 2, 1, 1, 12, 1, 3, 1, 3, 18, 16, 1, 3, 2, 2, 1, 12, 1, 3, 1, 1, 18, 18, 1, 1, 4, 1, 1, 2, 2, 9, 32, 1, 1, 1, 4, 27]

cp's OEIS Frontend

A306709 For n > 1, a(n) = gcd(A001414(n), A167344(n)) where A001414(n) is the sum of primes p dividing n (with repetition) and A167344(n) = b(n) is the totally multiplicative sequence with b(p) = (p-1)*(p+1) = p^2 - 1; a(1) = 0.

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	3
9	2
10	1
11	1
12	1
13	1
14	9
15	8
16	1
17	1
18	8
19	1
20	9
21	2
22	1
23	1
24	9
25	2
26	3
27	1
28	1
29	1
30	2
31	1
32	1
33	2
34	1
35	12
36	2
37	1
38	3
39	16
40	1
41	1
42	12
43	1
44	15
45	1
46	1
47	1
48	1
49	2
50	12
51	4
52	1
53	1
54	1
55	16
56	1
57	2
58	1
59	1
60	12
61	1
62	3
63	1
64	3
65	18
66	16
67	1
68	3
69	2
70	2
71	1
72	12
73	1
74	3
75	1
76	1
77	18
78	18
79	1
80	1
81	4
82	1
83	1
84	2
85	2
86	9
87	32
88	1
89	1
90	1
91	4
92	27

n	a(n)
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	3
9	2
10	1
11	1
12	1
13	1
14	9
15	8
16	1
17	1
18	8
19	1
20	9
21	2
22	1
23	1
24	9
25	2
26	3
27	1
28	1
29	1
30	2
31	1
32	1
33	2
34	1
35	12
36	2
37	1
38	3
39	16
40	1
41	1
42	12
43	1
44	15
45	1
46	1
47	1
48	1
49	2
50	12
51	4
52	1
53	1
54	1
55	16
56	1
57	2
58	1
59	1
60	12
61	1
62	3
63	1
64	3
65	18
66	16
67	1
68	3
69	2
70	2
71	1
72	12
73	1
74	3
75	1
76	1
77	18
78	18
79	1
80	1
81	4
82	1
83	1
84	2
85	2
86	9
87	32
88	1
89	1
90	1
91	4
92	27

n	a(n)
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	3
9	2
10	1
11	1
12	1
13	1
14	9
15	8
16	1
17	1
18	8
19	1
20	9
21	2
22	1
23	1
24	9
25	2
26	3
27	1
28	1
29	1
30	2
31	1
32	1
33	2
34	1
35	12
36	2
37	1
38	3
39	16
40	1
41	1
42	12
43	1
44	15
45	1
46	1
47	1
48	1
49	2
50	12
51	4
52	1
53	1
54	1
55	16
56	1
57	2
58	1
59	1
60	12
61	1
62	3
63	1
64	3
65	18
66	16
67	1
68	3
69	2
70	2
71	1
72	12
73	1
74	3
75	1
76	1
77	18
78	18
79	1
80	1
81	4
82	1
83	1
84	2
85	2
86	9
87	32
88	1
89	1
90	1
91	4
92	27