A219547 - cp's OEIS frontend

A219547 Numbers k such that 2 times the least prime factor of 2^k + 1 is not the least m > 1 that divides sigma_k(m).

n	a(n)
1	8
2	16
3	32
4	40
5	48
6	56
7	64
8	80
9	88
10	96
11	104
12	112
13	128
14	136
15	152
16	160
17	176
18	184
19	192
20	200
21	208
22	224
23	232
24	240
25	248
26	256
27	272
28	280
29	296
30	304
31	320
32	328
33	336
34	344
35	352
36	368
37	376
38	384
39	392
40	400
41	416
42	424
43	440
44	448
45	464
46	472
47	480
48	488
49	496

[8, 16, 32, 40, 48, 56, 64, 80, 88, 96, 104, 112, 128, 136, 152, 160, 176, 184, 192, 200, 208, 224, 232, 240, 248, 256, 272, 280, 296, 304, 320, 328, 336, 344, 352, 368, 376, 384, 392, 400, 416, 424, 440, 448, 464, 472, 480, 488, 496]

cp's OEIS Frontend

A219547 Numbers k such that 2 times the least prime factor of 2^k + 1 is not the least m > 1 that divides sigma_k(m).

Table of values

List of values

n	a(n)
1	8
2	16
3	32
4	40
5	48
6	56
7	64
8	80
9	88
10	96
11	104
12	112
13	128
14	136
15	152
16	160
17	176
18	184
19	192
20	200
21	208
22	224
23	232
24	240
25	248
26	256
27	272
28	280
29	296
30	304
31	320
32	328
33	336
34	344
35	352
36	368
37	376
38	384
39	392
40	400
41	416
42	424
43	440
44	448
45	464
46	472
47	480
48	488
49	496

n	a(n)
1	8
2	16
3	32
4	40
5	48
6	56
7	64
8	80
9	88
10	96
11	104
12	112
13	128
14	136
15	152
16	160
17	176
18	184
19	192
20	200
21	208
22	224
23	232
24	240
25	248
26	256
27	272
28	280
29	296
30	304
31	320
32	328
33	336
34	344
35	352
36	368
37	376
38	384
39	392
40	400
41	416
42	424
43	440
44	448
45	464
46	472
47	480
48	488
49	496

n	a(n)
1	8
2	16
3	32
4	40
5	48
6	56
7	64
8	80
9	88
10	96
11	104
12	112
13	128
14	136
15	152
16	160
17	176
18	184
19	192
20	200
21	208
22	224
23	232
24	240
25	248
26	256
27	272
28	280
29	296
30	304
31	320
32	328
33	336
34	344
35	352
36	368
37	376
38	384
39	392
40	400
41	416
42	424
43	440
44	448
45	464
46	472
47	480
48	488
49	496