A077646 - cp's OEIS frontend

A077646 Solutions to lcm(n, tau(n)) = 2n which are neither prime nor twice a prime, where tau(k) = d(k) is the number of divisors of k.

n	a(n)
1	45
2	63
3	75
4	90
5	99
6	117
7	120
8	126
9	147
10	150
11	153
12	168
13	171
14	198
15	207
16	216
17	234
18	243
19	261
20	264
21	279
22	280
23	294
24	306
25	312
26	333
27	342
28	363
29	369
30	387
31	405
32	408
33	414
34	420
35	423
36	440
37	456
38	477
39	486
40	507
41	520
42	522
43	531
44	540
45	549
46	552
47	558
48	603
49	616
50	639
51	657
52	660

[45, 63, 75, 90, 99, 117, 120, 126, 147, 150, 153, 168, 171, 198, 207, 216, 234, 243, 261, 264, 279, 280, 294, 306, 312, 333, 342, 363, 369, 387, 405, 408, 414, 420, 423, 440, 456, 477, 486, 507, 520, 522, 531, 540, 549, 552, 558, 603, 616, 639, 657, 660]

cp's OEIS Frontend

A077646 Solutions to lcm(n, tau(n)) = 2n which are neither prime nor twice a prime, where tau(k) = d(k) is the number of divisors of k.

Table of values

List of values

n	a(n)
1	45
2	63
3	75
4	90
5	99
6	117
7	120
8	126
9	147
10	150
11	153
12	168
13	171
14	198
15	207
16	216
17	234
18	243
19	261
20	264
21	279
22	280
23	294
24	306
25	312
26	333
27	342
28	363
29	369
30	387
31	405
32	408
33	414
34	420
35	423
36	440
37	456
38	477
39	486
40	507
41	520
42	522
43	531
44	540
45	549
46	552
47	558
48	603
49	616
50	639
51	657
52	660

n	a(n)
1	45
2	63
3	75
4	90
5	99
6	117
7	120
8	126
9	147
10	150
11	153
12	168
13	171
14	198
15	207
16	216
17	234
18	243
19	261
20	264
21	279
22	280
23	294
24	306
25	312
26	333
27	342
28	363
29	369
30	387
31	405
32	408
33	414
34	420
35	423
36	440
37	456
38	477
39	486
40	507
41	520
42	522
43	531
44	540
45	549
46	552
47	558
48	603
49	616
50	639
51	657
52	660

n	a(n)
1	45
2	63
3	75
4	90
5	99
6	117
7	120
8	126
9	147
10	150
11	153
12	168
13	171
14	198
15	207
16	216
17	234
18	243
19	261
20	264
21	279
22	280
23	294
24	306
25	312
26	333
27	342
28	363
29	369
30	387
31	405
32	408
33	414
34	420
35	423
36	440
37	456
38	477
39	486
40	507
41	520
42	522
43	531
44	540
45	549
46	552
47	558
48	603
49	616
50	639
51	657
52	660