A001912 - cp's OEIS frontend

A001912 Numbers k such that 4*k^2 + 1 is prime.

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	10
8	12
9	13
10	18
11	20
12	27
13	28
14	33
15	37
16	42
17	45
18	47
19	55
20	58
21	60
22	62
23	63
24	65
25	67
26	73
27	75
28	78
29	80
30	85
31	88
32	90
33	92
34	102
35	103
36	105
37	112
38	115
39	118
40	120
41	125
42	128
43	130
44	132
45	135
46	140
47	142
48	150
49	153
50	157
51	163
52	170
53	175
54	192
55	193
56	198
57	200

[1, 2, 3, 5, 7, 8, 10, 12, 13, 18, 20, 27, 28, 33, 37, 42, 45, 47, 55, 58, 60, 62, 63, 65, 67, 73, 75, 78, 80, 85, 88, 90, 92, 102, 103, 105, 112, 115, 118, 120, 125, 128, 130, 132, 135, 140, 142, 150, 153, 157, 163, 170, 175, 192, 193, 198, 200]

cp's OEIS Frontend

A001912 Numbers k such that 4*k^2 + 1 is prime.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	10
8	12
9	13
10	18
11	20
12	27
13	28
14	33
15	37
16	42
17	45
18	47
19	55
20	58
21	60
22	62
23	63
24	65
25	67
26	73
27	75
28	78
29	80
30	85
31	88
32	90
33	92
34	102
35	103
36	105
37	112
38	115
39	118
40	120
41	125
42	128
43	130
44	132
45	135
46	140
47	142
48	150
49	153
50	157
51	163
52	170
53	175
54	192
55	193
56	198
57	200

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	10
8	12
9	13
10	18
11	20
12	27
13	28
14	33
15	37
16	42
17	45
18	47
19	55
20	58
21	60
22	62
23	63
24	65
25	67
26	73
27	75
28	78
29	80
30	85
31	88
32	90
33	92
34	102
35	103
36	105
37	112
38	115
39	118
40	120
41	125
42	128
43	130
44	132
45	135
46	140
47	142
48	150
49	153
50	157
51	163
52	170
53	175
54	192
55	193
56	198
57	200

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	10
8	12
9	13
10	18
11	20
12	27
13	28
14	33
15	37
16	42
17	45
18	47
19	55
20	58
21	60
22	62
23	63
24	65
25	67
26	73
27	75
28	78
29	80
30	85
31	88
32	90
33	92
34	102
35	103
36	105
37	112
38	115
39	118
40	120
41	125
42	128
43	130
44	132
45	135
46	140
47	142
48	150
49	153
50	157
51	163
52	170
53	175
54	192
55	193
56	198
57	200