A143189 - cp's OEIS frontend

A143189 Numbers k such that at least one of the following equations holds: phi(2k-1) = phi(2k), sigma(2k-1) = sigma(2k), tau(2k-1) = tau(2k).

n	a(n)
1	1
2	2
3	8
4	11
5	17
6	29
7	38
8	43
9	47
10	67
11	68
12	71
13	73
14	74
15	86
16	89
17	95
18	101
19	103
20	107
21	109
22	116
23	122
24	127
25	128
26	143
27	151
28	188
29	191
30	194
31	197
32	215
33	223
34	227
35	241
36	248
37	251
38	254
39	269
40	277
41	283
42	302
43	305
44	317
45	323
46	332
47	349
48	359
49	368
50	371
51	373
52	397
53	403
54	409
55	410
56	433
57	452

[1, 2, 8, 11, 17, 29, 38, 43, 47, 67, 68, 71, 73, 74, 86, 89, 95, 101, 103, 107, 109, 116, 122, 127, 128, 143, 151, 188, 191, 194, 197, 215, 223, 227, 241, 248, 251, 254, 269, 277, 283, 302, 305, 317, 323, 332, 349, 359, 368, 371, 373, 397, 403, 409, 410, 433, 452]

cp's OEIS Frontend

A143189 Numbers k such that at least one of the following equations holds: phi(2k-1) = phi(2k), sigma(2k-1) = sigma(2k), tau(2k-1) = tau(2k).

Table of values

List of values

n	a(n)
1	1
2	2
3	8
4	11
5	17
6	29
7	38
8	43
9	47
10	67
11	68
12	71
13	73
14	74
15	86
16	89
17	95
18	101
19	103
20	107
21	109
22	116
23	122
24	127
25	128
26	143
27	151
28	188
29	191
30	194
31	197
32	215
33	223
34	227
35	241
36	248
37	251
38	254
39	269
40	277
41	283
42	302
43	305
44	317
45	323
46	332
47	349
48	359
49	368
50	371
51	373
52	397
53	403
54	409
55	410
56	433
57	452

n	a(n)
1	1
2	2
3	8
4	11
5	17
6	29
7	38
8	43
9	47
10	67
11	68
12	71
13	73
14	74
15	86
16	89
17	95
18	101
19	103
20	107
21	109
22	116
23	122
24	127
25	128
26	143
27	151
28	188
29	191
30	194
31	197
32	215
33	223
34	227
35	241
36	248
37	251
38	254
39	269
40	277
41	283
42	302
43	305
44	317
45	323
46	332
47	349
48	359
49	368
50	371
51	373
52	397
53	403
54	409
55	410
56	433
57	452

cp's OEIS Frontend

A143189 Numbers k such that at least one of the following equations holds: phi(2*k-1) = phi(2*k), sigma(2*k-1) = sigma(2*k), tau(2*k-1) = tau(2*k).

Table of values

List of values

A143189 Numbers k such that at least one of the following equations holds: phi(2k-1) = phi(2k), sigma(2k-1) = sigma(2k), tau(2k-1) = tau(2k).

n	a(n)
1	1
2	2
3	8
4	11
5	17
6	29
7	38
8	43
9	47
10	67
11	68
12	71
13	73
14	74
15	86
16	89
17	95
18	101
19	103
20	107
21	109
22	116
23	122
24	127
25	128
26	143
27	151
28	188
29	191
30	194
31	197
32	215
33	223
34	227
35	241
36	248
37	251
38	254
39	269
40	277
41	283
42	302
43	305
44	317
45	323
46	332
47	349
48	359
49	368
50	371
51	373
52	397
53	403
54	409
55	410
56	433
57	452