A330606 - cp's OEIS frontend

A330606 Numbers k such that k*d(k) and sigma(k) are relatively prime, where d(k) is the number of divisors of k (A000005) and sigma(k) is their sum (A000203).

n	a(n)
1	1
2	2
3	4
4	8
5	9
6	16
7	25
8	36
9	64
10	81
11	100
12	121
13	128
14	144
15	225
16	256
17	289
18	324
19	400
20	484
21	512
22	529
23	576
24	625
25	729
26	841
27	900
28	1024
29	1089
30	1156
31	1250
32	1296
33	1600
34	1681
35	1936
36	2025
37	2116
38	2209
39	2304
40	2401
41	2500
42	2601
43	2809
44	3025
45	3364
46	3481
47	3600
48	4096
49	4356
50	4624
51	4761

[1, 2, 4, 8, 9, 16, 25, 36, 64, 81, 100, 121, 128, 144, 225, 256, 289, 324, 400, 484, 512, 529, 576, 625, 729, 841, 900, 1024, 1089, 1156, 1250, 1296, 1600, 1681, 1936, 2025, 2116, 2209, 2304, 2401, 2500, 2601, 2809, 3025, 3364, 3481, 3600, 4096, 4356, 4624, 4761]

cp's OEIS Frontend

A330606 Numbers k such that k*d(k) and sigma(k) are relatively prime, where d(k) is the number of divisors of k (A000005) and sigma(k) is their sum (A000203).

Table of values

List of values