A173297 - cp's OEIS frontend

A173297 Numbers k such that exactly one of k^2 + k - 1 and k^2 + k + 1 is prime.

n	a(n)
1	1
2	4
3	9
4	10
5	11
6	12
7	13
8	14
9	16
10	17
11	19
12	26
13	27
14	28
15	30
16	31
17	33
18	35
19	39
20	44
21	45
22	46
23	48
24	53
25	55
26	56
27	57
28	60
29	62
30	64
31	65
32	68
33	69
34	70
35	71
36	75
37	76
38	77
39	78
40	80
41	83
42	85
43	86
44	90
45	93
46	94
47	96
48	99
49	100
50	103
51	105
52	110
53	111
54	114
55	115
56	117
57	119
58	120
59	125
60	126
61	130
62	134
63	140
64	143
65	144

[1, 4, 9, 10, 11, 12, 13, 14, 16, 17, 19, 26, 27, 28, 30, 31, 33, 35, 39, 44, 45, 46, 48, 53, 55, 56, 57, 60, 62, 64, 65, 68, 69, 70, 71, 75, 76, 77, 78, 80, 83, 85, 86, 90, 93, 94, 96, 99, 100, 103, 105, 110, 111, 114, 115, 117, 119, 120, 125, 126, 130, 134, 140, 143, 144]

cp's OEIS Frontend

A173297 Numbers k such that exactly one of k^2 + k - 1 and k^2 + k + 1 is prime.

Table of values

List of values

n	a(n)
1	1
2	4
3	9
4	10
5	11
6	12
7	13
8	14
9	16
10	17
11	19
12	26
13	27
14	28
15	30
16	31
17	33
18	35
19	39
20	44
21	45
22	46
23	48
24	53
25	55
26	56
27	57
28	60
29	62
30	64
31	65
32	68
33	69
34	70
35	71
36	75
37	76
38	77
39	78
40	80
41	83
42	85
43	86
44	90
45	93
46	94
47	96
48	99
49	100
50	103
51	105
52	110
53	111
54	114
55	115
56	117
57	119
58	120
59	125
60	126
61	130
62	134
63	140
64	143
65	144

n	a(n)
1	1
2	4
3	9
4	10
5	11
6	12
7	13
8	14
9	16
10	17
11	19
12	26
13	27
14	28
15	30
16	31
17	33
18	35
19	39
20	44
21	45
22	46
23	48
24	53
25	55
26	56
27	57
28	60
29	62
30	64
31	65
32	68
33	69
34	70
35	71
36	75
37	76
38	77
39	78
40	80
41	83
42	85
43	86
44	90
45	93
46	94
47	96
48	99
49	100
50	103
51	105
52	110
53	111
54	114
55	115
56	117
57	119
58	120
59	125
60	126
61	130
62	134
63	140
64	143
65	144

n	a(n)
1	1
2	4
3	9
4	10
5	11
6	12
7	13
8	14
9	16
10	17
11	19
12	26
13	27
14	28
15	30
16	31
17	33
18	35
19	39
20	44
21	45
22	46
23	48
24	53
25	55
26	56
27	57
28	60
29	62
30	64
31	65
32	68
33	69
34	70
35	71
36	75
37	76
38	77
39	78
40	80
41	83
42	85
43	86
44	90
45	93
46	94
47	96
48	99
49	100
50	103
51	105
52	110
53	111
54	114
55	115
56	117
57	119
58	120
59	125
60	126
61	130
62	134
63	140
64	143
65	144