A285906 - cp's OEIS frontend

A285906 Numbers n such that sigma(n)/usigma(n) > sigma(m)/usigma(m) for all m < n, where sigma(n) is the sum of divisors of n (A000203) and usigma(n) is the sum of unitary divisors of n (A034448).

n	a(n)
1	1
2	4
3	8
4	16
5	32
6	64
7	72
8	144
9	216
10	288
11	432
12	864
13	1728
14	2592
15	3456
16	3600
17	5184
18	7200
19	10800
20	21600
21	43200
22	64800
23	86400
24	108000
25	129600
26	216000
27	259200
28	324000
29	432000
30	518400
31	529200
32	648000
33	1058400
34	2116800
35	3175200
36	4233600
37	5292000
38	6350400
39	10584000

[1, 4, 8, 16, 32, 64, 72, 144, 216, 288, 432, 864, 1728, 2592, 3456, 3600, 5184, 7200, 10800, 21600, 43200, 64800, 86400, 108000, 129600, 216000, 259200, 324000, 432000, 518400, 529200, 648000, 1058400, 2116800, 3175200, 4233600, 5292000, 6350400, 10584000]

cp's OEIS Frontend

A285906 Numbers n such that sigma(n)/usigma(n) > sigma(m)/usigma(m) for all m < n, where sigma(n) is the sum of divisors of n (A000203) and usigma(n) is the sum of unitary divisors of n (A034448).

Table of values

List of values