A385676 - cp's OEIS frontend

A385676 Least prime p <= 2n^2 - n + 1 such that the polynomial Sum_{k=1..n} sigma(k) x^(n-k) is irreducible modulo p, or 1 if such p does not exist, where sigma is given by A000203.

n	a(n)
1	1
2	2
3	3
4	2
5	1
6	5
7	11
8	29
9	2
10	47
11	5
12	31
13	13
14	379
15	37
16	251
17	23
18	29
19	67
20	97
21	41
22	131
23	11
24	173
25	41
26	139
27	79
28	103
29	281
30	19
31	7
32	53
33	71
34	281
35	131
36	19
37	3
38	43
39	149
40	23
41	347
42	47
43	29
44	107
45	107
46	47
47	823
48	47
49	311
50	547
51	67
52	419
53	263
54	379
55	349
56	23
57	227
58	349
59	19
60	113

[1, 2, 3, 2, 1, 5, 11, 29, 2, 47, 5, 31, 13, 379, 37, 251, 23, 29, 67, 97, 41, 131, 11, 173, 41, 139, 79, 103, 281, 19, 7, 53, 71, 281, 131, 19, 3, 43, 149, 23, 347, 47, 29, 107, 107, 47, 823, 47, 311, 547, 67, 419, 263, 379, 349, 23, 227, 349, 19, 113]

cp's OEIS Frontend

A385676 Least prime p <= 2n^2 - n + 1 such that the polynomial Sum_{k=1..n} sigma(k) x^(n-k) is irreducible modulo p, or 1 if such p does not exist, where sigma is given by A000203.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	2
5	1
6	5
7	11
8	29
9	2
10	47
11	5
12	31
13	13
14	379
15	37
16	251
17	23
18	29
19	67
20	97
21	41
22	131
23	11
24	173
25	41
26	139
27	79
28	103
29	281
30	19
31	7
32	53
33	71
34	281
35	131
36	19
37	3
38	43
39	149
40	23
41	347
42	47
43	29
44	107
45	107
46	47
47	823
48	47
49	311
50	547
51	67
52	419
53	263
54	379
55	349
56	23
57	227
58	349
59	19
60	113

n	a(n)
1	1
2	2
3	3
4	2
5	1
6	5
7	11
8	29
9	2
10	47
11	5
12	31
13	13
14	379
15	37
16	251
17	23
18	29
19	67
20	97
21	41
22	131
23	11
24	173
25	41
26	139
27	79
28	103
29	281
30	19
31	7
32	53
33	71
34	281
35	131
36	19
37	3
38	43
39	149
40	23
41	347
42	47
43	29
44	107
45	107
46	47
47	823
48	47
49	311
50	547
51	67
52	419
53	263
54	379
55	349
56	23
57	227
58	349
59	19
60	113

cp's OEIS Frontend

A385676 Least prime p <= 2*n^2 - n + 1 such that the polynomial Sum_{k=1..n} sigma(k) * x^(n-k) is irreducible modulo p, or 1 if such p does not exist, where sigma is given by A000203.

Table of values

List of values

A385676 Least prime p <= 2n^2 - n + 1 such that the polynomial Sum_{k=1..n} sigma(k) x^(n-k) is irreducible modulo p, or 1 if such p does not exist, where sigma is given by A000203.

n	a(n)
1	1
2	2
3	3
4	2
5	1
6	5
7	11
8	29
9	2
10	47
11	5
12	31
13	13
14	379
15	37
16	251
17	23
18	29
19	67
20	97
21	41
22	131
23	11
24	173
25	41
26	139
27	79
28	103
29	281
30	19
31	7
32	53
33	71
34	281
35	131
36	19
37	3
38	43
39	149
40	23
41	347
42	47
43	29
44	107
45	107
46	47
47	823
48	47
49	311
50	547
51	67
52	419
53	263
54	379
55	349
56	23
57	227
58	349
59	19
60	113