A182003 - cp's OEIS frontend

A182003 a(n) = least prime p_k such that n = p_k - p_{k-1} + ... + (-1)^{k-j}p_j for some 1 <= j <= k, with p_k the k-th prime.

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

[3, 2, 3, 5, 5, 11, 7, 11, 11, 17, 11, 17, 13, 23, 17, 23, 17, 31, 19, 41, 23, 41, 23, 47, 29, 47, 37, 59, 29, 59, 31, 59, 43, 67, 37, 67, 37, 67, 43, 73, 41, 83, 43, 83, 47, 101, 47, 97, 53, 97, 59, 97, 53, 103, 61, 109, 67, 127, 59, 131]

cp's OEIS Frontend

A182003 a(n) = least prime p_k such that n = p_k - p_{k-1} + ... + (-1)^{k-j}p_j for some 1 <= j <= k, with p_k the k-th prime.

Table of values

List of values

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

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

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