A295305 - cp's OEIS frontend

A295305 a(n) = tau(sigma(n)) - tau(n), where tau is the number of divisors (A000005) and sigma is the sum of divisors of n (A000203).

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

[0, 0, 1, -1, 2, 2, 2, 0, -1, 2, 4, 0, 2, 4, 4, -3, 4, -2, 4, 2, 2, 5, 6, 4, -1, 4, 4, 2, 6, 4, 4, 0, 6, 4, 6, -5, 2, 8, 4, 4, 6, 4, 4, 6, 2, 8, 8, -4, 1, -2, 8, 0, 6, 8, 8, 8, 6, 8, 10, 4, 2, 8, 2, -5, 8, 7, 4, 6, 8, 7, 10, -4, 2, 4, 0, 6, 8, 8, 8, -2, -2, 8, 10, 0, 8, 8, 12, 10, 10, 0, 6, 10, 4, 11, 12, 6, 4, 0, 6, -5, 6, 8, 6, 8, 6]

cp's OEIS Frontend

A295305 a(n) = tau(sigma(n)) - tau(n), where tau is the number of divisors (A000005) and sigma is the sum of divisors of n (A000203).

Table of values

List of values

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

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

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