A376198 - cp's OEIS frontend

A376198 a(1) = 1, a(2) = 2. Thereafter, let smc and smp denote the smallest missing composite and smallest missing prime. If a(n) is composite, then if a(n) = 2*smp then a(n+1) = smp, otherwise a(n+1) = smc; if a(n) is a prime, then if smp < smc, a(n+1) = smp, otherwise a(n+1) = smc.

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	5
10	7
11	11
12	12
13	14
14	15
15	16
16	18
17	20
18	21
19	22
20	24
21	25
22	26
23	13
24	17
25	19
26	23
27	27
28	28
29	30
30	32
31	33
32	34
33	35
34	36
35	38
36	39
37	40
38	42
39	44
40	45
41	46
42	48
43	49
44	50
45	51
46	52
47	54
48	55
49	56
50	57
51	58
52	29
53	31
54	37
55	41
56	43
57	47
58	53
59	59
60	60
61	62
62	63
63	64
64	65
65	66
66	68
67	69
68	70
69	72
70	74
71	75
72	76
73	77
74	78
75	80
76	81
77	82
78	84
79	85
80	86
81	87
82	88
83	90
84	91
85	92
86	93
87	94

[1, 2, 3, 4, 6, 8, 9, 10, 5, 7, 11, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 13, 17, 19, 23, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 29, 31, 37, 41, 43, 47, 53, 59, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94]

cp's OEIS Frontend

A376198 a(1) = 1, a(2) = 2. Thereafter, let smc and smp denote the smallest missing composite and smallest missing prime. If a(n) is composite, then if a(n) = 2*smp then a(n+1) = smp, otherwise a(n+1) = smc; if a(n) is a prime, then if smp < smc, a(n+1) = smp, otherwise a(n+1) = smc.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	5
10	7
11	11
12	12
13	14
14	15
15	16
16	18
17	20
18	21
19	22
20	24
21	25
22	26
23	13
24	17
25	19
26	23
27	27
28	28
29	30
30	32
31	33
32	34
33	35
34	36
35	38
36	39
37	40
38	42
39	44
40	45
41	46
42	48
43	49
44	50
45	51
46	52
47	54
48	55
49	56
50	57
51	58
52	29
53	31
54	37
55	41
56	43
57	47
58	53
59	59
60	60
61	62
62	63
63	64
64	65
65	66
66	68
67	69
68	70
69	72
70	74
71	75
72	76
73	77
74	78
75	80
76	81
77	82
78	84
79	85
80	86
81	87
82	88
83	90
84	91
85	92
86	93
87	94

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	5
10	7
11	11
12	12
13	14
14	15
15	16
16	18
17	20
18	21
19	22
20	24
21	25
22	26
23	13
24	17
25	19
26	23
27	27
28	28
29	30
30	32
31	33
32	34
33	35
34	36
35	38
36	39
37	40
38	42
39	44
40	45
41	46
42	48
43	49
44	50
45	51
46	52
47	54
48	55
49	56
50	57
51	58
52	29
53	31
54	37
55	41
56	43
57	47
58	53
59	59
60	60
61	62
62	63
63	64
64	65
65	66
66	68
67	69
68	70
69	72
70	74
71	75
72	76
73	77
74	78
75	80
76	81
77	82
78	84
79	85
80	86
81	87
82	88
83	90
84	91
85	92
86	93
87	94

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	5
10	7
11	11
12	12
13	14
14	15
15	16
16	18
17	20
18	21
19	22
20	24
21	25
22	26
23	13
24	17
25	19
26	23
27	27
28	28
29	30
30	32
31	33
32	34
33	35
34	36
35	38
36	39
37	40
38	42
39	44
40	45
41	46
42	48
43	49
44	50
45	51
46	52
47	54
48	55
49	56
50	57
51	58
52	29
53	31
54	37
55	41
56	43
57	47
58	53
59	59
60	60
61	62
62	63
63	64
64	65
65	66
66	68
67	69
68	70
69	72
70	74
71	75
72	76
73	77
74	78
75	80
76	81
77	82
78	84
79	85
80	86
81	87
82	88
83	90
84	91
85	92
86	93
87	94