A387406 - cp's OEIS frontend

A387406 Numbers k such that sigma(A253560(k)) / A253560(k) is equal to (sigma(k)+1) / k, where A253560(k) = k multiplied by its largest prime factor.

n	a(n)
1	6
2	18
3	28
4	54
5	117
6	162
7	196
8	486
9	496
10	775
11	1372
12	1458
13	1521
14	4374
15	8128
16	9604
17	13122
18	15376
19	19773
20	24025
21	39366
22	67228
23	88723
24	118098
25	257049
26	354294
27	470596
28	476656
29	744775
30	796797
31	1032256
32	1062882
33	2896363
34	3188646
35	3294172
36	3341637
37	6725201
38	9565938
39	12326221
40	14776336
41	23059204
42	23088025
43	25774633
44	27237961

[6, 18, 28, 54, 117, 162, 196, 486, 496, 775, 1372, 1458, 1521, 4374, 8128, 9604, 13122, 15376, 19773, 24025, 39366, 67228, 88723, 118098, 257049, 354294, 470596, 476656, 744775, 796797, 1032256, 1062882, 2896363, 3188646, 3294172, 3341637, 6725201, 9565938, 12326221, 14776336, 23059204, 23088025, 25774633, 27237961]

cp's OEIS Frontend

A387406 Numbers k such that sigma(A253560(k)) / A253560(k) is equal to (sigma(k)+1) / k, where A253560(k) = k multiplied by its largest prime factor.

Table of values

List of values