A259916 - cp's OEIS frontend

A259916 Least positive integer k such that sigma(k) and phi(k*n) are both squares, where sigma(k) is the sum of all positive divisors of k, and phi(.) is Euler's totient function.

n	a(n)
1	1
2	1
3	210
4	3
5	1
6	170
7	81
8	1
9	70
10	1
11	400
12	1
13	210
14	81
15	357
16	3
17	1
18	119
19	3
20	3
21	3
22	651
23	1990
24	170
25	66
26	70
27	210
28	884
29	3810
30	357
31	1066
32	1
33	217
34	1
35	81
36	3
37	1
38	3
39	70
40	1
41	22
42	3
43	1624
44	217
45	119
46	3383
47	11510
48	1
49	364
50	22
51	210
52	81
53	8743
54	170
55	510
56	81
57	1
58	1270
59	2902
60	1
61	385
62	1155
63	1
64	3
65	357
66	217
67	966
68	3
69	4179
70	81

[1, 1, 210, 3, 1, 170, 81, 1, 70, 1, 400, 1, 210, 81, 357, 3, 1, 119, 3, 3, 3, 651, 1990, 170, 66, 70, 210, 884, 3810, 357, 1066, 1, 217, 1, 81, 3, 1, 3, 70, 1, 22, 3, 1624, 217, 119, 3383, 11510, 1, 364, 22, 210, 81, 8743, 170, 510, 81, 1, 1270, 2902, 1, 385, 1155, 1, 3, 357, 217, 966, 3, 4179, 81]

cp's OEIS Frontend

A259916 Least positive integer k such that sigma(k) and phi(k*n) are both squares, where sigma(k) is the sum of all positive divisors of k, and phi(.) is Euler's totient function.

Table of values

List of values