A351412 - cp's OEIS frontend

A351412 a(1) = 1, a(2) = 2, a(3) = 3. Then if n is even a(n) is the least positive integer not yet in the sequence, otherwise if n is odd a(n) = a(n-1) + a(n-3).

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	5
7	9
8	7
9	12
10	8
11	15
12	10
13	18
14	11
15	21
16	13
17	24
18	14
19	27
20	16
21	30
22	17
23	33
24	19
25	36
26	20
27	39
28	22
29	42
30	23
31	45
32	25
33	48
34	26
35	51
36	28
37	54
38	29
39	57
40	31
41	60
42	32
43	63
44	34
45	66
46	35
47	69
48	37
49	72
50	38
51	75
52	40
53	78
54	41
55	81
56	43
57	84
58	44
59	87
60	46
61	90
62	47
63	93
64	49
65	96
66	50
67	99
68	52
69	102
70	53
71	105
72	55
73	108
74	56
75	111
76	58
77	114
78	59
79	117

[1, 2, 3, 4, 6, 5, 9, 7, 12, 8, 15, 10, 18, 11, 21, 13, 24, 14, 27, 16, 30, 17, 33, 19, 36, 20, 39, 22, 42, 23, 45, 25, 48, 26, 51, 28, 54, 29, 57, 31, 60, 32, 63, 34, 66, 35, 69, 37, 72, 38, 75, 40, 78, 41, 81, 43, 84, 44, 87, 46, 90, 47, 93, 49, 96, 50, 99, 52, 102, 53, 105, 55, 108, 56, 111, 58, 114, 59, 117]

cp's OEIS Frontend

A351412 a(1) = 1, a(2) = 2, a(3) = 3. Then if n is even a(n) is the least positive integer not yet in the sequence, otherwise if n is odd a(n) = a(n-1) + a(n-3).

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	5
7	9
8	7
9	12
10	8
11	15
12	10
13	18
14	11
15	21
16	13
17	24
18	14
19	27
20	16
21	30
22	17
23	33
24	19
25	36
26	20
27	39
28	22
29	42
30	23
31	45
32	25
33	48
34	26
35	51
36	28
37	54
38	29
39	57
40	31
41	60
42	32
43	63
44	34
45	66
46	35
47	69
48	37
49	72
50	38
51	75
52	40
53	78
54	41
55	81
56	43
57	84
58	44
59	87
60	46
61	90
62	47
63	93
64	49
65	96
66	50
67	99
68	52
69	102
70	53
71	105
72	55
73	108
74	56
75	111
76	58
77	114
78	59
79	117

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	5
7	9
8	7
9	12
10	8
11	15
12	10
13	18
14	11
15	21
16	13
17	24
18	14
19	27
20	16
21	30
22	17
23	33
24	19
25	36
26	20
27	39
28	22
29	42
30	23
31	45
32	25
33	48
34	26
35	51
36	28
37	54
38	29
39	57
40	31
41	60
42	32
43	63
44	34
45	66
46	35
47	69
48	37
49	72
50	38
51	75
52	40
53	78
54	41
55	81
56	43
57	84
58	44
59	87
60	46
61	90
62	47
63	93
64	49
65	96
66	50
67	99
68	52
69	102
70	53
71	105
72	55
73	108
74	56
75	111
76	58
77	114
78	59
79	117

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	5
7	9
8	7
9	12
10	8
11	15
12	10
13	18
14	11
15	21
16	13
17	24
18	14
19	27
20	16
21	30
22	17
23	33
24	19
25	36
26	20
27	39
28	22
29	42
30	23
31	45
32	25
33	48
34	26
35	51
36	28
37	54
38	29
39	57
40	31
41	60
42	32
43	63
44	34
45	66
46	35
47	69
48	37
49	72
50	38
51	75
52	40
53	78
54	41
55	81
56	43
57	84
58	44
59	87
60	46
61	90
62	47
63	93
64	49
65	96
66	50
67	99
68	52
69	102
70	53
71	105
72	55
73	108
74	56
75	111
76	58
77	114
78	59
79	117