A118967 - cp's OEIS frontend

A118967 If n doesn't occur among the first (n-1) terms of the sequence, then a(n) = 2n. If n occurs among the first (n-1) terms of the sequence, then a(n) = n/2.

n	a(n)
1	1
2	4
3	6
4	2
5	10
6	3
7	14
8	16
9	18
10	5
11	22
12	24
13	26
14	7
15	30
16	8
17	34
18	9
19	38
20	40
21	42
22	11
23	46
24	12
25	50
26	13
27	54
28	56
29	58
30	15
31	62
32	64
33	66
34	17
35	70
36	72
37	74
38	19
39	78
40	20
41	82
42	21
43	86
44	88
45	90
46	23
47	94
48	96
49	98
50	25
51	102
52	104
53	106
54	27
55	110
56	28
57	114
58	29
59	118
60	120
61	122
62	31
63	126
64	32
65	130
66	33
67	134
68	136

[1, 4, 6, 2, 10, 3, 14, 16, 18, 5, 22, 24, 26, 7, 30, 8, 34, 9, 38, 40, 42, 11, 46, 12, 50, 13, 54, 56, 58, 15, 62, 64, 66, 17, 70, 72, 74, 19, 78, 20, 82, 21, 86, 88, 90, 23, 94, 96, 98, 25, 102, 104, 106, 27, 110, 28, 114, 29, 118, 120, 122, 31, 126, 32, 130, 33, 134, 136]

cp's OEIS Frontend

A118967 If n doesn't occur among the first (n-1) terms of the sequence, then a(n) = 2n. If n occurs among the first (n-1) terms of the sequence, then a(n) = n/2.

Table of values

List of values

n	a(n)
1	1
2	4
3	6
4	2
5	10
6	3
7	14
8	16
9	18
10	5
11	22
12	24
13	26
14	7
15	30
16	8
17	34
18	9
19	38
20	40
21	42
22	11
23	46
24	12
25	50
26	13
27	54
28	56
29	58
30	15
31	62
32	64
33	66
34	17
35	70
36	72
37	74
38	19
39	78
40	20
41	82
42	21
43	86
44	88
45	90
46	23
47	94
48	96
49	98
50	25
51	102
52	104
53	106
54	27
55	110
56	28
57	114
58	29
59	118
60	120
61	122
62	31
63	126
64	32
65	130
66	33
67	134
68	136

n	a(n)
1	1
2	4
3	6
4	2
5	10
6	3
7	14
8	16
9	18
10	5
11	22
12	24
13	26
14	7
15	30
16	8
17	34
18	9
19	38
20	40
21	42
22	11
23	46
24	12
25	50
26	13
27	54
28	56
29	58
30	15
31	62
32	64
33	66
34	17
35	70
36	72
37	74
38	19
39	78
40	20
41	82
42	21
43	86
44	88
45	90
46	23
47	94
48	96
49	98
50	25
51	102
52	104
53	106
54	27
55	110
56	28
57	114
58	29
59	118
60	120
61	122
62	31
63	126
64	32
65	130
66	33
67	134
68	136

n	a(n)
1	1
2	4
3	6
4	2
5	10
6	3
7	14
8	16
9	18
10	5
11	22
12	24
13	26
14	7
15	30
16	8
17	34
18	9
19	38
20	40
21	42
22	11
23	46
24	12
25	50
26	13
27	54
28	56
29	58
30	15
31	62
32	64
33	66
34	17
35	70
36	72
37	74
38	19
39	78
40	20
41	82
42	21
43	86
44	88
45	90
46	23
47	94
48	96
49	98
50	25
51	102
52	104
53	106
54	27
55	110
56	28
57	114
58	29
59	118
60	120
61	122
62	31
63	126
64	32
65	130
66	33
67	134
68	136