A072780 - cp's OEIS frontend

A072780 a(n) = sigma_2(n) + phi(n) * sigma(n) - 2n^2, which is A072779(n) - 2n^2.

n	a(n)
1	0
2	0
3	0
4	3
5	0
6	2
7	0
8	17
9	7
10	2
11	0
12	34
13	0
14	2
15	2
16	77
17	0
18	41
19	0
20	82
21	2
22	2
23	0
24	178
25	21
26	2
27	82
28	154
29	0
30	76
31	0
32	325
33	2
34	2
35	2
36	411
37	0
38	2
39	2
40	450
41	0
42	124
43	0
44	370
45	188
46	2
47	0
48	786
49	43
50	115
51	2
52	514
53	0
54	428
55	2
56	858
57	2
58	2
59	0
60	948
61	0
62	2
63	356
64	1333
65	2
66	268
67	0
68	874
69	2
70	156
71	0
72	2047
73	0
74	2
75	220

[0, 0, 0, 3, 0, 2, 0, 17, 7, 2, 0, 34, 0, 2, 2, 77, 0, 41, 0, 82, 2, 2, 0, 178, 21, 2, 82, 154, 0, 76, 0, 325, 2, 2, 2, 411, 0, 2, 2, 450, 0, 124, 0, 370, 188, 2, 0, 786, 43, 115, 2, 514, 0, 428, 2, 858, 2, 2, 0, 948, 0, 2, 356, 1333, 2, 268, 0, 874, 2, 156, 0, 2047, 0, 2, 220]

cp's OEIS Frontend

A072780 a(n) = sigma_2(n) + phi(n) * sigma(n) - 2n^2, which is A072779(n) - 2n^2.

Table of values

List of values

cp's OEIS Frontend

A072780 a(n) = sigma_2(n) + phi(n) * sigma(n) - 2*n^2, which is A072779(n) - 2*n^2.

Table of values

List of values

A072780 a(n) = sigma_2(n) + phi(n) * sigma(n) - 2n^2, which is A072779(n) - 2n^2.