A165199 - cp's OEIS frontend

A165199 a(n) is obtained by flipping every second bit in the binary representation of n starting at the second-most significant bit and on downwards.

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	7
6	4
7	5
8	13
9	12
10	15
11	14
12	9
13	8
14	11
15	10
16	26
17	27
18	24
19	25
20	30
21	31
22	28
23	29
24	18
25	19
26	16
27	17
28	22
29	23
30	20
31	21
32	53
33	52
34	55
35	54
36	49
37	48
38	51
39	50
40	61
41	60
42	63
43	62
44	57
45	56
46	59
47	58
48	37
49	36
50	39
51	38
52	33
53	32
54	35
55	34
56	45
57	44
58	47
59	46
60	41
61	40
62	43
63	42
64	106
65	107
66	104
67	105
68	110
69	111
70	108

[0, 1, 3, 2, 6, 7, 4, 5, 13, 12, 15, 14, 9, 8, 11, 10, 26, 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22, 23, 20, 21, 53, 52, 55, 54, 49, 48, 51, 50, 61, 60, 63, 62, 57, 56, 59, 58, 37, 36, 39, 38, 33, 32, 35, 34, 45, 44, 47, 46, 41, 40, 43, 42, 106, 107, 104, 105, 110, 111, 108]

cp's OEIS Frontend

A165199 a(n) is obtained by flipping every second bit in the binary representation of n starting at the second-most significant bit and on downwards.

Table of values

List of values

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	7
6	4
7	5
8	13
9	12
10	15
11	14
12	9
13	8
14	11
15	10
16	26
17	27
18	24
19	25
20	30
21	31
22	28
23	29
24	18
25	19
26	16
27	17
28	22
29	23
30	20
31	21
32	53
33	52
34	55
35	54
36	49
37	48
38	51
39	50
40	61
41	60
42	63
43	62
44	57
45	56
46	59
47	58
48	37
49	36
50	39
51	38
52	33
53	32
54	35
55	34
56	45
57	44
58	47
59	46
60	41
61	40
62	43
63	42
64	106
65	107
66	104
67	105
68	110
69	111
70	108

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	7
6	4
7	5
8	13
9	12
10	15
11	14
12	9
13	8
14	11
15	10
16	26
17	27
18	24
19	25
20	30
21	31
22	28
23	29
24	18
25	19
26	16
27	17
28	22
29	23
30	20
31	21
32	53
33	52
34	55
35	54
36	49
37	48
38	51
39	50
40	61
41	60
42	63
43	62
44	57
45	56
46	59
47	58
48	37
49	36
50	39
51	38
52	33
53	32
54	35
55	34
56	45
57	44
58	47
59	46
60	41
61	40
62	43
63	42
64	106
65	107
66	104
67	105
68	110
69	111
70	108

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	7
6	4
7	5
8	13
9	12
10	15
11	14
12	9
13	8
14	11
15	10
16	26
17	27
18	24
19	25
20	30
21	31
22	28
23	29
24	18
25	19
26	16
27	17
28	22
29	23
30	20
31	21
32	53
33	52
34	55
35	54
36	49
37	48
38	51
39	50
40	61
41	60
42	63
43	62
44	57
45	56
46	59
47	58
48	37
49	36
50	39
51	38
52	33
53	32
54	35
55	34
56	45
57	44
58	47
59	46
60	41
61	40
62	43
63	42
64	106
65	107
66	104
67	105
68	110
69	111
70	108