A130280 - cp's OEIS frontend

A130280 a(n) = smallest integer k>1 such that n(k^2-1)+1 is a perfect square, or 0 if no such number exists.

n	a(n)
1	2
2	5
3	3
4	0
5	2
6	3
7	5
8	2
9	0
10	3
11	7
12	5
13	4
14	11
15	3
16	2
17	4
18	13
19	9
20	7
21	2
22	5
23	19
24	4
25	0
26	5
27	21
28	3
29	11
30	9
31	11
32	14
33	2
34	29
35	5
36	3
37	6
38	31
39	21
40	2
41	13
42	11
43	13
44	169
45	3
46	7
47	41
48	6
49	0
50	7
51	5
52	11
53	22
54	419
55	3
56	2
57	5
58	23
59	461
60	27
61	8
62	55
63	7
64	4
65	2
66	3
67	49
68	29

[2, 5, 3, 0, 2, 3, 5, 2, 0, 3, 7, 5, 4, 11, 3, 2, 4, 13, 9, 7, 2, 5, 19, 4, 0, 5, 21, 3, 11, 9, 11, 14, 2, 29, 5, 3, 6, 31, 21, 2, 13, 11, 13, 169, 3, 7, 41, 6, 0, 7, 5, 11, 22, 419, 3, 2, 5, 23, 461, 27, 8, 55, 7, 4, 2, 3, 49, 29]

cp's OEIS Frontend

A130280 a(n) = smallest integer k>1 such that n(k^2-1)+1 is a perfect square, or 0 if no such number exists.

Table of values

List of values

n	a(n)
1	2
2	5
3	3
4	0
5	2
6	3
7	5
8	2
9	0
10	3
11	7
12	5
13	4
14	11
15	3
16	2
17	4
18	13
19	9
20	7
21	2
22	5
23	19
24	4
25	0
26	5
27	21
28	3
29	11
30	9
31	11
32	14
33	2
34	29
35	5
36	3
37	6
38	31
39	21
40	2
41	13
42	11
43	13
44	169
45	3
46	7
47	41
48	6
49	0
50	7
51	5
52	11
53	22
54	419
55	3
56	2
57	5
58	23
59	461
60	27
61	8
62	55
63	7
64	4
65	2
66	3
67	49
68	29

n	a(n)
1	2
2	5
3	3
4	0
5	2
6	3
7	5
8	2
9	0
10	3
11	7
12	5
13	4
14	11
15	3
16	2
17	4
18	13
19	9
20	7
21	2
22	5
23	19
24	4
25	0
26	5
27	21
28	3
29	11
30	9
31	11
32	14
33	2
34	29
35	5
36	3
37	6
38	31
39	21
40	2
41	13
42	11
43	13
44	169
45	3
46	7
47	41
48	6
49	0
50	7
51	5
52	11
53	22
54	419
55	3
56	2
57	5
58	23
59	461
60	27
61	8
62	55
63	7
64	4
65	2
66	3
67	49
68	29

n	a(n)
1	2
2	5
3	3
4	0
5	2
6	3
7	5
8	2
9	0
10	3
11	7
12	5
13	4
14	11
15	3
16	2
17	4
18	13
19	9
20	7
21	2
22	5
23	19
24	4
25	0
26	5
27	21
28	3
29	11
30	9
31	11
32	14
33	2
34	29
35	5
36	3
37	6
38	31
39	21
40	2
41	13
42	11
43	13
44	169
45	3
46	7
47	41
48	6
49	0
50	7
51	5
52	11
53	22
54	419
55	3
56	2
57	5
58	23
59	461
60	27
61	8
62	55
63	7
64	4
65	2
66	3
67	49
68	29