A137671 - cp's OEIS frontend

A137671 a(n+1) is the number of preceding terms having in binary representation the same number of ones as a(n), starting with a(1) = 1.

n	a(n)
1	1
2	1
3	2
4	3
5	1
6	4
7	5
8	2
9	6
10	3
11	4
12	7
13	1
14	8
15	9
16	5
17	6
18	7
19	2
20	10
21	8
22	11
23	3
24	9
25	10
26	11
27	4
28	12
29	12
30	13
31	5
32	14
33	6
34	15
35	1
36	13
37	7
38	8
39	14
40	9
41	16
42	15
43	2
44	16
45	17
46	17
47	18
48	19
49	10
50	20
51	21
52	11
53	12
54	22
55	13
56	14
57	15
58	3
59	23
60	4
61	18
62	24
63	25
64	16
65	19
66	17
67	26
68	18
69	27
70	5
71	28
72	19
73	20
74	29
75	6
76	30
77	7
78	21
79	22
80	23
81	8

[1, 1, 2, 3, 1, 4, 5, 2, 6, 3, 4, 7, 1, 8, 9, 5, 6, 7, 2, 10, 8, 11, 3, 9, 10, 11, 4, 12, 12, 13, 5, 14, 6, 15, 1, 13, 7, 8, 14, 9, 16, 15, 2, 16, 17, 17, 18, 19, 10, 20, 21, 11, 12, 22, 13, 14, 15, 3, 23, 4, 18, 24, 25, 16, 19, 17, 26, 18, 27, 5, 28, 19, 20, 29, 6, 30, 7, 21, 22, 23, 8]

cp's OEIS Frontend

A137671 a(n+1) is the number of preceding terms having in binary representation the same number of ones as a(n), starting with a(1) = 1.

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	3
5	1
6	4
7	5
8	2
9	6
10	3
11	4
12	7
13	1
14	8
15	9
16	5
17	6
18	7
19	2
20	10
21	8
22	11
23	3
24	9
25	10
26	11
27	4
28	12
29	12
30	13
31	5
32	14
33	6
34	15
35	1
36	13
37	7
38	8
39	14
40	9
41	16
42	15
43	2
44	16
45	17
46	17
47	18
48	19
49	10
50	20
51	21
52	11
53	12
54	22
55	13
56	14
57	15
58	3
59	23
60	4
61	18
62	24
63	25
64	16
65	19
66	17
67	26
68	18
69	27
70	5
71	28
72	19
73	20
74	29
75	6
76	30
77	7
78	21
79	22
80	23
81	8

n	a(n)
1	1
2	1
3	2
4	3
5	1
6	4
7	5
8	2
9	6
10	3
11	4
12	7
13	1
14	8
15	9
16	5
17	6
18	7
19	2
20	10
21	8
22	11
23	3
24	9
25	10
26	11
27	4
28	12
29	12
30	13
31	5
32	14
33	6
34	15
35	1
36	13
37	7
38	8
39	14
40	9
41	16
42	15
43	2
44	16
45	17
46	17
47	18
48	19
49	10
50	20
51	21
52	11
53	12
54	22
55	13
56	14
57	15
58	3
59	23
60	4
61	18
62	24
63	25
64	16
65	19
66	17
67	26
68	18
69	27
70	5
71	28
72	19
73	20
74	29
75	6
76	30
77	7
78	21
79	22
80	23
81	8

n	a(n)
1	1
2	1
3	2
4	3
5	1
6	4
7	5
8	2
9	6
10	3
11	4
12	7
13	1
14	8
15	9
16	5
17	6
18	7
19	2
20	10
21	8
22	11
23	3
24	9
25	10
26	11
27	4
28	12
29	12
30	13
31	5
32	14
33	6
34	15
35	1
36	13
37	7
38	8
39	14
40	9
41	16
42	15
43	2
44	16
45	17
46	17
47	18
48	19
49	10
50	20
51	21
52	11
53	12
54	22
55	13
56	14
57	15
58	3
59	23
60	4
61	18
62	24
63	25
64	16
65	19
66	17
67	26
68	18
69	27
70	5
71	28
72	19
73	20
74	29
75	6
76	30
77	7
78	21
79	22
80	23
81	8