A110177 - cp's OEIS frontend

A110177 Number of solutions 0 to the equation sigma(n) = sigma(k) + sigma(n-k), where sigma is the sum of divisors function.

n	a(n)
1	0
2	0
3	2
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	0
12	0
13	0
14	0
15	2
16	0
17	0
18	0
19	0
20	2
21	2
22	0
23	0
24	0
25	0
26	0
27	0
28	0
29	0
30	2
31	0
32	4
33	2
34	0
35	0
36	0
37	0
38	0
39	2
40	2
41	0
42	0
43	0
44	0
45	0
46	0
47	0
48	0
49	2
50	0
51	2
52	0
53	0
54	0
55	4
56	2
57	4
58	0
59	0
60	0
61	0
62	2
63	4
64	0
65	0
66	0
67	0
68	0
69	4
70	2
71	0
72	0
73	0
74	0
75	2
76	0
77	0
78	0
79	0
80	0
81	0
82	0
83	0
84	0
85	2
86	0
87	4
88	2
89	0
90	2
91	0
92	2
93	2
94	2
95	0
96	2
97	0
98	0
99	2
100	0
101	0
102	0
103	0
104	2
105	4

[0, 0, 2, 0, 0, 0, 0, 2, 2, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 4, 2, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 4, 2, 4, 0, 0, 0, 0, 2, 4, 0, 0, 0, 0, 0, 4, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 4, 2, 0, 2, 0, 2, 2, 2, 0, 2, 0, 0, 2, 0, 0, 0, 0, 2, 4]

cp's OEIS Frontend

A110177 Number of solutions 0 to the equation sigma(n) = sigma(k) + sigma(n-k), where sigma is the sum of divisors function.

Table of values

List of values

n	a(n)
1	0
2	0
3	2
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	0
12	0
13	0
14	0
15	2
16	0
17	0
18	0
19	0
20	2
21	2
22	0
23	0
24	0
25	0
26	0
27	0
28	0
29	0
30	2
31	0
32	4
33	2
34	0
35	0
36	0
37	0
38	0
39	2
40	2
41	0
42	0
43	0
44	0
45	0
46	0
47	0
48	0
49	2
50	0
51	2
52	0
53	0
54	0
55	4
56	2
57	4
58	0
59	0
60	0
61	0
62	2
63	4
64	0
65	0
66	0
67	0
68	0
69	4
70	2
71	0
72	0
73	0
74	0
75	2
76	0
77	0
78	0
79	0
80	0
81	0
82	0
83	0
84	0
85	2
86	0
87	4
88	2
89	0
90	2
91	0
92	2
93	2
94	2
95	0
96	2
97	0
98	0
99	2
100	0
101	0
102	0
103	0
104	2
105	4

n	a(n)
1	0
2	0
3	2
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	0
12	0
13	0
14	0
15	2
16	0
17	0
18	0
19	0
20	2
21	2
22	0
23	0
24	0
25	0
26	0
27	0
28	0
29	0
30	2
31	0
32	4
33	2
34	0
35	0
36	0
37	0
38	0
39	2
40	2
41	0
42	0
43	0
44	0
45	0
46	0
47	0
48	0
49	2
50	0
51	2
52	0
53	0
54	0
55	4
56	2
57	4
58	0
59	0
60	0
61	0
62	2
63	4
64	0
65	0
66	0
67	0
68	0
69	4
70	2
71	0
72	0
73	0
74	0
75	2
76	0
77	0
78	0
79	0
80	0
81	0
82	0
83	0
84	0
85	2
86	0
87	4
88	2
89	0
90	2
91	0
92	2
93	2
94	2
95	0
96	2
97	0
98	0
99	2
100	0
101	0
102	0
103	0
104	2
105	4

n	a(n)
1	0
2	0
3	2
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	0
12	0
13	0
14	0
15	2
16	0
17	0
18	0
19	0
20	2
21	2
22	0
23	0
24	0
25	0
26	0
27	0
28	0
29	0
30	2
31	0
32	4
33	2
34	0
35	0
36	0
37	0
38	0
39	2
40	2
41	0
42	0
43	0
44	0
45	0
46	0
47	0
48	0
49	2
50	0
51	2
52	0
53	0
54	0
55	4
56	2
57	4
58	0
59	0
60	0
61	0
62	2
63	4
64	0
65	0
66	0
67	0
68	0
69	4
70	2
71	0
72	0
73	0
74	0
75	2
76	0
77	0
78	0
79	0
80	0
81	0
82	0
83	0
84	0
85	2
86	0
87	4
88	2
89	0
90	2
91	0
92	2
93	2
94	2
95	0
96	2
97	0
98	0
99	2
100	0
101	0
102	0
103	0
104	2
105	4