A210882 - cp's OEIS frontend

A210882 a(1)=1, a(n)=a(n-1)-1 if a(n-1)-1 > 0 is not in the set {a(k)| 1<=k else a(n)=p, where p is the least prime number not yet in the sequence.

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

[1, 2, 3, 5, 4, 7, 6, 11, 10, 9, 8, 13, 12, 17, 16, 15, 14, 19, 18, 23, 22, 21, 20, 29, 28, 27, 26, 25, 24, 31, 30, 37, 36, 35, 34, 33, 32, 41, 40, 39, 38, 43, 42, 47, 46, 45, 44, 53, 52, 51, 50, 49, 48, 59, 58, 57, 56, 55, 54, 61, 60, 67, 66, 65, 64, 63, 62, 71]

cp's OEIS Frontend

A210882 a(1)=1, a(n)=a(n-1)-1 if a(n-1)-1 > 0 is not in the set {a(k)| 1<=k else a(n)=p, where p is the least prime number not yet in the sequence.

Table of values

List of values

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

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

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