A368231 - cp's OEIS frontend

A368231 Lexicographically earliest infinite sequence of distinct positive numbers such that, for n>3, a(n) has a common factor with a(n-1) but not with a(n-2) or n.

n	a(n)
1	1
2	15
3	35
4	77
5	143
6	65
7	30
8	21
9	91
10	221
11	85
12	55
13	33
14	39
15	182
16	133
17	95
18	115
19	69
20	51
21	170
22	145
23	203
24	119
25	102
26	45
27	155
28	341
29	154
30	161
31	207
32	57
33	190
34	185
35	407
36	187
37	153
38	63
39	217
40	403
41	130
42	205
43	123
44	87
45	319
46	209
47	247
48	299
49	138
50	93
51	589
52	323
53	238
54	259
55	111
56	75
57	70
58	287
59	451
60	253
61	230
62	195
63	377

[1, 15, 35, 77, 143, 65, 30, 21, 91, 221, 85, 55, 33, 39, 182, 133, 95, 115, 69, 51, 170, 145, 203, 119, 102, 45, 155, 341, 154, 161, 207, 57, 190, 185, 407, 187, 153, 63, 217, 403, 130, 205, 123, 87, 319, 209, 247, 299, 138, 93, 589, 323, 238, 259, 111, 75, 70, 287, 451, 253, 230, 195, 377]

cp's OEIS Frontend

A368231 Lexicographically earliest infinite sequence of distinct positive numbers such that, for n>3, a(n) has a common factor with a(n-1) but not with a(n-2) or n.

Table of values

List of values

n	a(n)
1	1
2	15
3	35
4	77
5	143
6	65
7	30
8	21
9	91
10	221
11	85
12	55
13	33
14	39
15	182
16	133
17	95
18	115
19	69
20	51
21	170
22	145
23	203
24	119
25	102
26	45
27	155
28	341
29	154
30	161
31	207
32	57
33	190
34	185
35	407
36	187
37	153
38	63
39	217
40	403
41	130
42	205
43	123
44	87
45	319
46	209
47	247
48	299
49	138
50	93
51	589
52	323
53	238
54	259
55	111
56	75
57	70
58	287
59	451
60	253
61	230
62	195
63	377

n	a(n)
1	1
2	15
3	35
4	77
5	143
6	65
7	30
8	21
9	91
10	221
11	85
12	55
13	33
14	39
15	182
16	133
17	95
18	115
19	69
20	51
21	170
22	145
23	203
24	119
25	102
26	45
27	155
28	341
29	154
30	161
31	207
32	57
33	190
34	185
35	407
36	187
37	153
38	63
39	217
40	403
41	130
42	205
43	123
44	87
45	319
46	209
47	247
48	299
49	138
50	93
51	589
52	323
53	238
54	259
55	111
56	75
57	70
58	287
59	451
60	253
61	230
62	195
63	377

n	a(n)
1	1
2	15
3	35
4	77
5	143
6	65
7	30
8	21
9	91
10	221
11	85
12	55
13	33
14	39
15	182
16	133
17	95
18	115
19	69
20	51
21	170
22	145
23	203
24	119
25	102
26	45
27	155
28	341
29	154
30	161
31	207
32	57
33	190
34	185
35	407
36	187
37	153
38	63
39	217
40	403
41	130
42	205
43	123
44	87
45	319
46	209
47	247
48	299
49	138
50	93
51	589
52	323
53	238
54	259
55	111
56	75
57	70
58	287
59	451
60	253
61	230
62	195
63	377