A280590 - cp's OEIS frontend

A280590 Numbers k such that for any positive integers (a, b), if a * b = k then sigma(a) + sigma(b) is a prime.

n	a(n)
1	1
2	3
3	5
4	6
5	11
6	17
7	24
8	26
9	27
10	29
11	38
12	41
13	59
14	71
15	101
16	107
17	125
18	137
19	149
20	158
21	179
22	191
23	197
24	206
25	218
26	227
27	239
28	269
29	281
30	311
31	344
32	347
33	419
34	431
35	446
36	458
37	461
38	521
39	536
40	569
41	599
42	617
43	641
44	659
45	698
46	809
47	821
48	827
49	857
50	878
51	881
52	1019
53	1031
54	1049
55	1061

[1, 3, 5, 6, 11, 17, 24, 26, 27, 29, 38, 41, 59, 71, 101, 107, 125, 137, 149, 158, 179, 191, 197, 206, 218, 227, 239, 269, 281, 311, 344, 347, 419, 431, 446, 458, 461, 521, 536, 569, 599, 617, 641, 659, 698, 809, 821, 827, 857, 878, 881, 1019, 1031, 1049, 1061]

cp's OEIS Frontend

A280590 Numbers k such that for any positive integers (a, b), if a * b = k then sigma(a) + sigma(b) is a prime.

Table of values

List of values