A082500 - cp's OEIS frontend

A082500 a(n) = ceiling(n/2) if n is odd, or prime(n/2) otherwise.

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	4
8	7
9	5
10	11
11	6
12	13
13	7
14	17
15	8
16	19
17	9
18	23
19	10
20	29
21	11
22	31
23	12
24	37
25	13
26	41
27	14
28	43
29	15
30	47
31	16
32	53
33	17
34	59
35	18
36	61
37	19
38	67
39	20
40	71
41	21
42	73
43	22
44	79
45	23
46	83
47	24
48	89
49	25
50	97
51	26
52	101
53	27
54	103
55	28
56	107
57	29
58	109
59	30
60	113
61	31
62	127
63	32
64	131
65	33
66	137
67	34
68	139
69	35
70	149
71	36

[1, 2, 2, 3, 3, 5, 4, 7, 5, 11, 6, 13, 7, 17, 8, 19, 9, 23, 10, 29, 11, 31, 12, 37, 13, 41, 14, 43, 15, 47, 16, 53, 17, 59, 18, 61, 19, 67, 20, 71, 21, 73, 22, 79, 23, 83, 24, 89, 25, 97, 26, 101, 27, 103, 28, 107, 29, 109, 30, 113, 31, 127, 32, 131, 33, 137, 34, 139, 35, 149, 36]

cp's OEIS Frontend

A082500 a(n) = ceiling(n/2) if n is odd, or prime(n/2) otherwise.

Table of values

List of values

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	4
8	7
9	5
10	11
11	6
12	13
13	7
14	17
15	8
16	19
17	9
18	23
19	10
20	29
21	11
22	31
23	12
24	37
25	13
26	41
27	14
28	43
29	15
30	47
31	16
32	53
33	17
34	59
35	18
36	61
37	19
38	67
39	20
40	71
41	21
42	73
43	22
44	79
45	23
46	83
47	24
48	89
49	25
50	97
51	26
52	101
53	27
54	103
55	28
56	107
57	29
58	109
59	30
60	113
61	31
62	127
63	32
64	131
65	33
66	137
67	34
68	139
69	35
70	149
71	36

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	4
8	7
9	5
10	11
11	6
12	13
13	7
14	17
15	8
16	19
17	9
18	23
19	10
20	29
21	11
22	31
23	12
24	37
25	13
26	41
27	14
28	43
29	15
30	47
31	16
32	53
33	17
34	59
35	18
36	61
37	19
38	67
39	20
40	71
41	21
42	73
43	22
44	79
45	23
46	83
47	24
48	89
49	25
50	97
51	26
52	101
53	27
54	103
55	28
56	107
57	29
58	109
59	30
60	113
61	31
62	127
63	32
64	131
65	33
66	137
67	34
68	139
69	35
70	149
71	36

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	4
8	7
9	5
10	11
11	6
12	13
13	7
14	17
15	8
16	19
17	9
18	23
19	10
20	29
21	11
22	31
23	12
24	37
25	13
26	41
27	14
28	43
29	15
30	47
31	16
32	53
33	17
34	59
35	18
36	61
37	19
38	67
39	20
40	71
41	21
42	73
43	22
44	79
45	23
46	83
47	24
48	89
49	25
50	97
51	26
52	101
53	27
54	103
55	28
56	107
57	29
58	109
59	30
60	113
61	31
62	127
63	32
64	131
65	33
66	137
67	34
68	139
69	35
70	149
71	36