A043687 - cp's OEIS frontend

A043687 a(n) = (s(n)-1)/2, where s(n) is the n-th number whose base-2 representation has exactly 3 runs.

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	11
8	12
9	13
10	14
11	16
12	17
13	19
14	23
15	24
16	25
17	27
18	28
19	29
20	30
21	32
22	33
23	35
24	39
25	47
26	48
27	49
28	51
29	55
30	56
31	57
32	59
33	60
34	61
35	62
36	64
37	65
38	67
39	71
40	79
41	95
42	96
43	97
44	99
45	103
46	111
47	112
48	113
49	115
50	119
51	120
52	121
53	123
54	124
55	125
56	126
57	128
58	129

[2, 4, 5, 6, 8, 9, 11, 12, 13, 14, 16, 17, 19, 23, 24, 25, 27, 28, 29, 30, 32, 33, 35, 39, 47, 48, 49, 51, 55, 56, 57, 59, 60, 61, 62, 64, 65, 67, 71, 79, 95, 96, 97, 99, 103, 111, 112, 113, 115, 119, 120, 121, 123, 124, 125, 126, 128, 129]

cp's OEIS Frontend

A043687 a(n) = (s(n)-1)/2, where s(n) is the n-th number whose base-2 representation has exactly 3 runs.

Table of values

List of values

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	11
8	12
9	13
10	14
11	16
12	17
13	19
14	23
15	24
16	25
17	27
18	28
19	29
20	30
21	32
22	33
23	35
24	39
25	47
26	48
27	49
28	51
29	55
30	56
31	57
32	59
33	60
34	61
35	62
36	64
37	65
38	67
39	71
40	79
41	95
42	96
43	97
44	99
45	103
46	111
47	112
48	113
49	115
50	119
51	120
52	121
53	123
54	124
55	125
56	126
57	128
58	129

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	11
8	12
9	13
10	14
11	16
12	17
13	19
14	23
15	24
16	25
17	27
18	28
19	29
20	30
21	32
22	33
23	35
24	39
25	47
26	48
27	49
28	51
29	55
30	56
31	57
32	59
33	60
34	61
35	62
36	64
37	65
38	67
39	71
40	79
41	95
42	96
43	97
44	99
45	103
46	111
47	112
48	113
49	115
50	119
51	120
52	121
53	123
54	124
55	125
56	126
57	128
58	129

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	11
8	12
9	13
10	14
11	16
12	17
13	19
14	23
15	24
16	25
17	27
18	28
19	29
20	30
21	32
22	33
23	35
24	39
25	47
26	48
27	49
28	51
29	55
30	56
31	57
32	59
33	60
34	61
35	62
36	64
37	65
38	67
39	71
40	79
41	95
42	96
43	97
44	99
45	103
46	111
47	112
48	113
49	115
50	119
51	120
52	121
53	123
54	124
55	125
56	126
57	128
58	129