A102568 - cp's OEIS frontend

A102568 a(n+1) = if a(n-1)=a(n)-1 then 2*a(n) else smallest number not occurring earlier; a(1)=1, a(2)=2.

n	a(n)
1	1
2	2
3	4
4	3
5	5
6	6
7	12
8	7
9	8
10	16
11	9
12	10
13	20
14	11
15	13
16	14
17	28
18	15
19	17
20	18
21	36
22	19
23	21
24	22
25	44
26	23
27	24
28	48
29	25
30	26
31	52
32	27
33	29
34	30
35	60
36	31
37	32
38	64
39	33
40	34
41	68
42	35
43	37
44	38
45	76
46	39
47	40
48	80
49	41
50	42
51	84
52	43
53	45
54	46
55	92
56	47
57	49
58	50
59	100
60	51
61	53
62	54
63	108
64	55
65	56
66	112
67	57
68	58
69	116
70	59
71	61

[1, 2, 4, 3, 5, 6, 12, 7, 8, 16, 9, 10, 20, 11, 13, 14, 28, 15, 17, 18, 36, 19, 21, 22, 44, 23, 24, 48, 25, 26, 52, 27, 29, 30, 60, 31, 32, 64, 33, 34, 68, 35, 37, 38, 76, 39, 40, 80, 41, 42, 84, 43, 45, 46, 92, 47, 49, 50, 100, 51, 53, 54, 108, 55, 56, 112, 57, 58, 116, 59, 61]

cp's OEIS Frontend

A102568 a(n+1) = if a(n-1)=a(n)-1 then 2*a(n) else smallest number not occurring earlier; a(1)=1, a(2)=2.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	3
5	5
6	6
7	12
8	7
9	8
10	16
11	9
12	10
13	20
14	11
15	13
16	14
17	28
18	15
19	17
20	18
21	36
22	19
23	21
24	22
25	44
26	23
27	24
28	48
29	25
30	26
31	52
32	27
33	29
34	30
35	60
36	31
37	32
38	64
39	33
40	34
41	68
42	35
43	37
44	38
45	76
46	39
47	40
48	80
49	41
50	42
51	84
52	43
53	45
54	46
55	92
56	47
57	49
58	50
59	100
60	51
61	53
62	54
63	108
64	55
65	56
66	112
67	57
68	58
69	116
70	59
71	61

n	a(n)
1	1
2	2
3	4
4	3
5	5
6	6
7	12
8	7
9	8
10	16
11	9
12	10
13	20
14	11
15	13
16	14
17	28
18	15
19	17
20	18
21	36
22	19
23	21
24	22
25	44
26	23
27	24
28	48
29	25
30	26
31	52
32	27
33	29
34	30
35	60
36	31
37	32
38	64
39	33
40	34
41	68
42	35
43	37
44	38
45	76
46	39
47	40
48	80
49	41
50	42
51	84
52	43
53	45
54	46
55	92
56	47
57	49
58	50
59	100
60	51
61	53
62	54
63	108
64	55
65	56
66	112
67	57
68	58
69	116
70	59
71	61

n	a(n)
1	1
2	2
3	4
4	3
5	5
6	6
7	12
8	7
9	8
10	16
11	9
12	10
13	20
14	11
15	13
16	14
17	28
18	15
19	17
20	18
21	36
22	19
23	21
24	22
25	44
26	23
27	24
28	48
29	25
30	26
31	52
32	27
33	29
34	30
35	60
36	31
37	32
38	64
39	33
40	34
41	68
42	35
43	37
44	38
45	76
46	39
47	40
48	80
49	41
50	42
51	84
52	43
53	45
54	46
55	92
56	47
57	49
58	50
59	100
60	51
61	53
62	54
63	108
64	55
65	56
66	112
67	57
68	58
69	116
70	59
71	61