A090780 - cp's OEIS frontend

A090780 a(n) = n*Product_{p prime, p|n} (p - 1)/2.

n	a(n)
1	1
2	1
3	3
4	2
5	10
6	3
7	21
8	4
9	9
10	10
11	55
12	6
13	78
14	21
15	30
16	8
17	136
18	9
19	171
20	20
21	63
22	55
23	253
24	12
25	50
26	78
27	27
28	42
29	406
30	30
31	465
32	16
33	165
34	136
35	210
36	18
37	666
38	171
39	234
40	40
41	820
42	63
43	903
44	110
45	90
46	253
47	1081
48	24
49	147
50	50
51	408
52	156
53	1378
54	27
55	550
56	84
57	513
58	406
59	1711
60	60
61	1830
62	465
63	189

[1, 1, 3, 2, 10, 3, 21, 4, 9, 10, 55, 6, 78, 21, 30, 8, 136, 9, 171, 20, 63, 55, 253, 12, 50, 78, 27, 42, 406, 30, 465, 16, 165, 136, 210, 18, 666, 171, 234, 40, 820, 63, 903, 110, 90, 253, 1081, 24, 147, 50, 408, 156, 1378, 27, 550, 84, 513, 406, 1711, 60, 1830, 465, 189]

cp's OEIS Frontend

A090780 a(n) = n*Product_{p prime, p|n} (p - 1)/2.

Table of values

List of values