A175880 - cp's OEIS frontend

A175880 a(1)=1, a(2)=2. If n >= 3: if n/2 is in the sequence, a(n)=0, otherwise a(n)=n.

n	a(n)
1	1
2	2
3	3
4	0
5	5
6	0
7	7
8	8
9	9
10	0
11	11
12	12
13	13
14	0
15	15
16	0
17	17
18	0
19	19
20	20
21	21
22	0
23	23
24	0
25	25
26	0
27	27
28	28
29	29
30	0
31	31
32	32
33	33
34	0
35	35
36	36
37	37
38	0
39	39
40	0
41	41
42	0
43	43
44	44
45	45
46	0
47	47
48	48
49	49
50	0
51	51
52	52
53	53
54	0
55	55
56	0
57	57
58	0
59	59
60	60
61	61
62	0
63	63
64	0
65	65
66	0
67	67
68	68
69	69
70	0
71	71
72	0
73	73
74	0
75	75
76	76
77	77
78	0
79	79
80	80

[1, 2, 3, 0, 5, 0, 7, 8, 9, 0, 11, 12, 13, 0, 15, 0, 17, 0, 19, 20, 21, 0, 23, 0, 25, 0, 27, 28, 29, 0, 31, 32, 33, 0, 35, 36, 37, 0, 39, 0, 41, 0, 43, 44, 45, 0, 47, 48, 49, 0, 51, 52, 53, 0, 55, 0, 57, 0, 59, 60, 61, 0, 63, 0, 65, 0, 67, 68, 69, 0, 71, 0, 73, 0, 75, 76, 77, 0, 79, 80]

cp's OEIS Frontend

A175880 a(1)=1, a(2)=2. If n >= 3: if n/2 is in the sequence, a(n)=0, otherwise a(n)=n.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	0
5	5
6	0
7	7
8	8
9	9
10	0
11	11
12	12
13	13
14	0
15	15
16	0
17	17
18	0
19	19
20	20
21	21
22	0
23	23
24	0
25	25
26	0
27	27
28	28
29	29
30	0
31	31
32	32
33	33
34	0
35	35
36	36
37	37
38	0
39	39
40	0
41	41
42	0
43	43
44	44
45	45
46	0
47	47
48	48
49	49
50	0
51	51
52	52
53	53
54	0
55	55
56	0
57	57
58	0
59	59
60	60
61	61
62	0
63	63
64	0
65	65
66	0
67	67
68	68
69	69
70	0
71	71
72	0
73	73
74	0
75	75
76	76
77	77
78	0
79	79
80	80

n	a(n)
1	1
2	2
3	3
4	0
5	5
6	0
7	7
8	8
9	9
10	0
11	11
12	12
13	13
14	0
15	15
16	0
17	17
18	0
19	19
20	20
21	21
22	0
23	23
24	0
25	25
26	0
27	27
28	28
29	29
30	0
31	31
32	32
33	33
34	0
35	35
36	36
37	37
38	0
39	39
40	0
41	41
42	0
43	43
44	44
45	45
46	0
47	47
48	48
49	49
50	0
51	51
52	52
53	53
54	0
55	55
56	0
57	57
58	0
59	59
60	60
61	61
62	0
63	63
64	0
65	65
66	0
67	67
68	68
69	69
70	0
71	71
72	0
73	73
74	0
75	75
76	76
77	77
78	0
79	79
80	80

n	a(n)
1	1
2	2
3	3
4	0
5	5
6	0
7	7
8	8
9	9
10	0
11	11
12	12
13	13
14	0
15	15
16	0
17	17
18	0
19	19
20	20
21	21
22	0
23	23
24	0
25	25
26	0
27	27
28	28
29	29
30	0
31	31
32	32
33	33
34	0
35	35
36	36
37	37
38	0
39	39
40	0
41	41
42	0
43	43
44	44
45	45
46	0
47	47
48	48
49	49
50	0
51	51
52	52
53	53
54	0
55	55
56	0
57	57
58	0
59	59
60	60
61	61
62	0
63	63
64	0
65	65
66	0
67	67
68	68
69	69
70	0
71	71
72	0
73	73
74	0
75	75
76	76
77	77
78	0
79	79
80	80