A353989 - cp's OEIS frontend

A353989 a(1) = 1; a(2) = 3; for n > 2, a(n) is the smallest positive number that has not appeared that shares a factor with a(n-1) and whose binary expansion has a 1-bit in common with the binary expansion of a(n-1).

n	a(n)
1	1
2	3
3	6
4	2
5	10
6	8
7	12
8	4
9	14
10	7
11	21
12	9
13	15
14	5
15	20
16	16
17	18
18	22
19	11
20	33
21	27
22	24
23	26
24	13
25	39
26	30
27	25
28	35
29	40
30	28
31	36
32	32
33	34
34	38
35	19
36	57
37	42
38	44
39	46
40	23
41	69
42	45
43	48
44	50
45	52
46	54
47	51
48	17
49	85
50	55
51	60
52	56
53	49
54	63
55	66
56	58
57	29
58	87
59	72
60	62
61	31
62	93
63	75
64	65
65	70
66	64
67	68
68	74
69	76
70	78
71	80
72	82
73	84
74	77
75	88
76	86
77	43

[1, 3, 6, 2, 10, 8, 12, 4, 14, 7, 21, 9, 15, 5, 20, 16, 18, 22, 11, 33, 27, 24, 26, 13, 39, 30, 25, 35, 40, 28, 36, 32, 34, 38, 19, 57, 42, 44, 46, 23, 69, 45, 48, 50, 52, 54, 51, 17, 85, 55, 60, 56, 49, 63, 66, 58, 29, 87, 72, 62, 31, 93, 75, 65, 70, 64, 68, 74, 76, 78, 80, 82, 84, 77, 88, 86, 43]

cp's OEIS Frontend

A353989 a(1) = 1; a(2) = 3; for n > 2, a(n) is the smallest positive number that has not appeared that shares a factor with a(n-1) and whose binary expansion has a 1-bit in common with the binary expansion of a(n-1).

Table of values

List of values

n	a(n)
1	1
2	3
3	6
4	2
5	10
6	8
7	12
8	4
9	14
10	7
11	21
12	9
13	15
14	5
15	20
16	16
17	18
18	22
19	11
20	33
21	27
22	24
23	26
24	13
25	39
26	30
27	25
28	35
29	40
30	28
31	36
32	32
33	34
34	38
35	19
36	57
37	42
38	44
39	46
40	23
41	69
42	45
43	48
44	50
45	52
46	54
47	51
48	17
49	85
50	55
51	60
52	56
53	49
54	63
55	66
56	58
57	29
58	87
59	72
60	62
61	31
62	93
63	75
64	65
65	70
66	64
67	68
68	74
69	76
70	78
71	80
72	82
73	84
74	77
75	88
76	86
77	43

n	a(n)
1	1
2	3
3	6
4	2
5	10
6	8
7	12
8	4
9	14
10	7
11	21
12	9
13	15
14	5
15	20
16	16
17	18
18	22
19	11
20	33
21	27
22	24
23	26
24	13
25	39
26	30
27	25
28	35
29	40
30	28
31	36
32	32
33	34
34	38
35	19
36	57
37	42
38	44
39	46
40	23
41	69
42	45
43	48
44	50
45	52
46	54
47	51
48	17
49	85
50	55
51	60
52	56
53	49
54	63
55	66
56	58
57	29
58	87
59	72
60	62
61	31
62	93
63	75
64	65
65	70
66	64
67	68
68	74
69	76
70	78
71	80
72	82
73	84
74	77
75	88
76	86
77	43

n	a(n)
1	1
2	3
3	6
4	2
5	10
6	8
7	12
8	4
9	14
10	7
11	21
12	9
13	15
14	5
15	20
16	16
17	18
18	22
19	11
20	33
21	27
22	24
23	26
24	13
25	39
26	30
27	25
28	35
29	40
30	28
31	36
32	32
33	34
34	38
35	19
36	57
37	42
38	44
39	46
40	23
41	69
42	45
43	48
44	50
45	52
46	54
47	51
48	17
49	85
50	55
51	60
52	56
53	49
54	63
55	66
56	58
57	29
58	87
59	72
60	62
61	31
62	93
63	75
64	65
65	70
66	64
67	68
68	74
69	76
70	78
71	80
72	82
73	84
74	77
75	88
76	86
77	43