A020493 - cp's OEIS frontend

A020493 Numbers k such that d(k) (number of divisors) divides phi(k) (Euler function) divides sigma(k) (sum of divisors).

n	a(n)
1	1
2	3
3	15
4	30
5	35
6	56
7	70
8	78
9	105
10	140
11	168
12	190
13	210
14	248
15	264
16	357
17	420
18	570
19	616
20	630
21	714
22	744
23	812
24	840
25	910
26	1045
27	1240
28	1485
29	1672
30	1848
31	2090
32	2214
33	2436
34	2580
35	2730
36	3080
37	3135
38	3339
39	3596
40	3720
41	3956
42	4064
43	4180
44	4522
45	4674
46	5016
47	5049
48	5278
49	5396

[1, 3, 15, 30, 35, 56, 70, 78, 105, 140, 168, 190, 210, 248, 264, 357, 420, 570, 616, 630, 714, 744, 812, 840, 910, 1045, 1240, 1485, 1672, 1848, 2090, 2214, 2436, 2580, 2730, 3080, 3135, 3339, 3596, 3720, 3956, 4064, 4180, 4522, 4674, 5016, 5049, 5278, 5396]

cp's OEIS Frontend

A020493 Numbers k such that d(k) (number of divisors) divides phi(k) (Euler function) divides sigma(k) (sum of divisors).

Table of values

List of values