A317420 - cp's OEIS frontend

A317420 a(n) = number of k with 1 <= k <= n-1 such that a(k) AND a(n-k) = a(k) (where AND denotes the bitwise AND operator).

n	a(n)
1	0
2	1
3	1
4	2
5	3
6	2
7	2
8	3
9	2
10	5
11	5
12	5
13	9
14	6
15	6
16	5
17	2
18	4
19	3
20	3
21	8
22	8
23	8
24	8
25	5
26	8
27	7
28	9
29	6
30	5
31	4
32	6
33	5
34	5
35	7
36	11
37	8
38	7
39	8
40	7
41	13
42	10
43	15
44	16
45	16
46	18
47	14
48	9
49	15
50	15
51	11
52	14
53	11
54	12
55	13
56	14
57	12
58	17
59	16
60	18
61	18
62	14
63	16
64	15
65	18
66	14
67	17
68	14
69	16
70	17
71	15
72	17
73	18
74	17
75	18

[0, 1, 1, 2, 3, 2, 2, 3, 2, 5, 5, 5, 9, 6, 6, 5, 2, 4, 3, 3, 8, 8, 8, 8, 5, 8, 7, 9, 6, 5, 4, 6, 5, 5, 7, 11, 8, 7, 8, 7, 13, 10, 15, 16, 16, 18, 14, 9, 15, 15, 11, 14, 11, 12, 13, 14, 12, 17, 16, 18, 18, 14, 16, 15, 18, 14, 17, 14, 16, 17, 15, 17, 18, 17, 18]

cp's OEIS Frontend

A317420 a(n) = number of k with 1 <= k <= n-1 such that a(k) AND a(n-k) = a(k) (where AND denotes the bitwise AND operator).

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	2
5	3
6	2
7	2
8	3
9	2
10	5
11	5
12	5
13	9
14	6
15	6
16	5
17	2
18	4
19	3
20	3
21	8
22	8
23	8
24	8
25	5
26	8
27	7
28	9
29	6
30	5
31	4
32	6
33	5
34	5
35	7
36	11
37	8
38	7
39	8
40	7
41	13
42	10
43	15
44	16
45	16
46	18
47	14
48	9
49	15
50	15
51	11
52	14
53	11
54	12
55	13
56	14
57	12
58	17
59	16
60	18
61	18
62	14
63	16
64	15
65	18
66	14
67	17
68	14
69	16
70	17
71	15
72	17
73	18
74	17
75	18

n	a(n)
1	0
2	1
3	1
4	2
5	3
6	2
7	2
8	3
9	2
10	5
11	5
12	5
13	9
14	6
15	6
16	5
17	2
18	4
19	3
20	3
21	8
22	8
23	8
24	8
25	5
26	8
27	7
28	9
29	6
30	5
31	4
32	6
33	5
34	5
35	7
36	11
37	8
38	7
39	8
40	7
41	13
42	10
43	15
44	16
45	16
46	18
47	14
48	9
49	15
50	15
51	11
52	14
53	11
54	12
55	13
56	14
57	12
58	17
59	16
60	18
61	18
62	14
63	16
64	15
65	18
66	14
67	17
68	14
69	16
70	17
71	15
72	17
73	18
74	17
75	18

n	a(n)
1	0
2	1
3	1
4	2
5	3
6	2
7	2
8	3
9	2
10	5
11	5
12	5
13	9
14	6
15	6
16	5
17	2
18	4
19	3
20	3
21	8
22	8
23	8
24	8
25	5
26	8
27	7
28	9
29	6
30	5
31	4
32	6
33	5
34	5
35	7
36	11
37	8
38	7
39	8
40	7
41	13
42	10
43	15
44	16
45	16
46	18
47	14
48	9
49	15
50	15
51	11
52	14
53	11
54	12
55	13
56	14
57	12
58	17
59	16
60	18
61	18
62	14
63	16
64	15
65	18
66	14
67	17
68	14
69	16
70	17
71	15
72	17
73	18
74	17
75	18