A181901 - cp's OEIS frontend

A181901 a(n) = least positive integer m such that 2(s_k)^2 for k=1,...,n are pairwise distinct modulo m where s_k = Sum_{j=1..k} (-1)^(k-j)*p_j and p_j is the j-th prime.

n	a(n)
1	1
2	4
3	7
4	9
5	13
6	17
7	19
8	23
9	25
10	31
11	37
12	41
13	43
14	47
15	53
16	59
17	61
18	67
19	71
20	73
21	79
22	83
23	89
24	97
25	101
26	103
27	107
28	109
29	113
30	127
31	131
32	137
33	139
34	149
35	151
36	157
37	163
38	167
39	173
40	179
41	181
42	191
43	193
44	197
45	199
46	211
47	223
48	227
49	229
50	233

[1, 4, 7, 9, 13, 17, 19, 23, 25, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233]

cp's OEIS Frontend

A181901 a(n) = least positive integer m such that 2(s_k)^2 for k=1,...,n are pairwise distinct modulo m where s_k = Sum_{j=1..k} (-1)^(k-j)*p_j and p_j is the j-th prime.

Table of values

List of values

n	a(n)
1	1
2	4
3	7
4	9
5	13
6	17
7	19
8	23
9	25
10	31
11	37
12	41
13	43
14	47
15	53
16	59
17	61
18	67
19	71
20	73
21	79
22	83
23	89
24	97
25	101
26	103
27	107
28	109
29	113
30	127
31	131
32	137
33	139
34	149
35	151
36	157
37	163
38	167
39	173
40	179
41	181
42	191
43	193
44	197
45	199
46	211
47	223
48	227
49	229
50	233

n	a(n)
1	1
2	4
3	7
4	9
5	13
6	17
7	19
8	23
9	25
10	31
11	37
12	41
13	43
14	47
15	53
16	59
17	61
18	67
19	71
20	73
21	79
22	83
23	89
24	97
25	101
26	103
27	107
28	109
29	113
30	127
31	131
32	137
33	139
34	149
35	151
36	157
37	163
38	167
39	173
40	179
41	181
42	191
43	193
44	197
45	199
46	211
47	223
48	227
49	229
50	233

n	a(n)
1	1
2	4
3	7
4	9
5	13
6	17
7	19
8	23
9	25
10	31
11	37
12	41
13	43
14	47
15	53
16	59
17	61
18	67
19	71
20	73
21	79
22	83
23	89
24	97
25	101
26	103
27	107
28	109
29	113
30	127
31	131
32	137
33	139
34	149
35	151
36	157
37	163
38	167
39	173
40	179
41	181
42	191
43	193
44	197
45	199
46	211
47	223
48	227
49	229
50	233