A343502 - cp's OEIS frontend

A343502 Numbers k such that tau(tau(k)) and tau(k+1) are both prime, where tau is the number of divisors function.

n	a(n)
1	2
2	3
3	4
4	6
5	8
6	10
7	15
8	16
9	22
10	36
11	46
12	58
13	82
14	100
15	106
16	120
17	166
18	168
19	178
20	196
21	210
22	226
23	256
24	262
25	270
26	280
27	312
28	330
29	346
30	358
31	378
32	382
33	408
34	456
35	462
36	466
37	478
38	502
39	520
40	546
41	562
42	570
43	586
44	616
45	640
46	676
47	690
48	718
49	728
50	750
51	760
52	838
53	858
54	862
55	886

[2, 3, 4, 6, 8, 10, 15, 16, 22, 36, 46, 58, 82, 100, 106, 120, 166, 168, 178, 196, 210, 226, 256, 262, 270, 280, 312, 330, 346, 358, 378, 382, 408, 456, 462, 466, 478, 502, 520, 546, 562, 570, 586, 616, 640, 676, 690, 718, 728, 750, 760, 838, 858, 862, 886]

cp's OEIS Frontend

A343502 Numbers k such that tau(tau(k)) and tau(k+1) are both prime, where tau is the number of divisors function.

Table of values

List of values

n	a(n)
1	2
2	3
3	4
4	6
5	8
6	10
7	15
8	16
9	22
10	36
11	46
12	58
13	82
14	100
15	106
16	120
17	166
18	168
19	178
20	196
21	210
22	226
23	256
24	262
25	270
26	280
27	312
28	330
29	346
30	358
31	378
32	382
33	408
34	456
35	462
36	466
37	478
38	502
39	520
40	546
41	562
42	570
43	586
44	616
45	640
46	676
47	690
48	718
49	728
50	750
51	760
52	838
53	858
54	862
55	886

n	a(n)
1	2
2	3
3	4
4	6
5	8
6	10
7	15
8	16
9	22
10	36
11	46
12	58
13	82
14	100
15	106
16	120
17	166
18	168
19	178
20	196
21	210
22	226
23	256
24	262
25	270
26	280
27	312
28	330
29	346
30	358
31	378
32	382
33	408
34	456
35	462
36	466
37	478
38	502
39	520
40	546
41	562
42	570
43	586
44	616
45	640
46	676
47	690
48	718
49	728
50	750
51	760
52	838
53	858
54	862
55	886

n	a(n)
1	2
2	3
3	4
4	6
5	8
6	10
7	15
8	16
9	22
10	36
11	46
12	58
13	82
14	100
15	106
16	120
17	166
18	168
19	178
20	196
21	210
22	226
23	256
24	262
25	270
26	280
27	312
28	330
29	346
30	358
31	378
32	382
33	408
34	456
35	462
36	466
37	478
38	502
39	520
40	546
41	562
42	570
43	586
44	616
45	640
46	676
47	690
48	718
49	728
50	750
51	760
52	838
53	858
54	862
55	886