A011257 - cp's OEIS frontend

A011257 Numbers k such that the geometric mean of phi(k) and sigma(k) is an integer.

n	a(n)
1	1
2	14
3	30
4	51
5	105
6	170
7	194
8	248
9	264
10	364
11	405
12	418
13	477
14	595
15	679
16	714
17	760
18	780
19	1023
20	1455
21	1463
22	1485
23	1496
24	1512
25	1524
26	1674
27	1715
28	1731
29	1796
30	1804
31	2058
32	2080
33	2651
34	2754
35	2945
36	3080
37	3135
38	3192
39	3410
40	3534
41	3567
42	3596
43	3828
44	3956
45	4064
46	4381
47	4420

[1, 14, 30, 51, 105, 170, 194, 248, 264, 364, 405, 418, 477, 595, 679, 714, 760, 780, 1023, 1455, 1463, 1485, 1496, 1512, 1524, 1674, 1715, 1731, 1796, 1804, 2058, 2080, 2651, 2754, 2945, 3080, 3135, 3192, 3410, 3534, 3567, 3596, 3828, 3956, 4064, 4381, 4420]

cp's OEIS Frontend

A011257 Numbers k such that the geometric mean of phi(k) and sigma(k) is an integer.

Table of values

List of values