A300473 - cp's OEIS frontend

A300473 Numbers k with the property that k^2 + 21k + 1 is prime.

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	13
14	14
15	15
16	16
17	17
18	19
19	20
20	21
21	22
22	23
23	25
24	26
25	27
26	28
27	29
28	30
29	31
30	32
31	33
32	34
33	36
34	38
35	39
36	40
37	41
38	42
39	43
40	44
41	45
42	46
43	48
44	51
45	52
46	53
47	54
48	57
49	58
50	59
51	60
52	61
53	62
54	64
55	65
56	66
57	67
58	68
59	69
60	73
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85
69	86
70	87
71	89
72	91
73	97
74	100

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 36, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 73, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 89, 91, 97, 100]

cp's OEIS Frontend

A300473 Numbers k with the property that k^2 + 21k + 1 is prime.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	13
14	14
15	15
16	16
17	17
18	19
19	20
20	21
21	22
22	23
23	25
24	26
25	27
26	28
27	29
28	30
29	31
30	32
31	33
32	34
33	36
34	38
35	39
36	40
37	41
38	42
39	43
40	44
41	45
42	46
43	48
44	51
45	52
46	53
47	54
48	57
49	58
50	59
51	60
52	61
53	62
54	64
55	65
56	66
57	67
58	68
59	69
60	73
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85
69	86
70	87
71	89
72	91
73	97
74	100

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	13
14	14
15	15
16	16
17	17
18	19
19	20
20	21
21	22
22	23
23	25
24	26
25	27
26	28
27	29
28	30
29	31
30	32
31	33
32	34
33	36
34	38
35	39
36	40
37	41
38	42
39	43
40	44
41	45
42	46
43	48
44	51
45	52
46	53
47	54
48	57
49	58
50	59
51	60
52	61
53	62
54	64
55	65
56	66
57	67
58	68
59	69
60	73
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85
69	86
70	87
71	89
72	91
73	97
74	100

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	13
14	14
15	15
16	16
17	17
18	19
19	20
20	21
21	22
22	23
23	25
24	26
25	27
26	28
27	29
28	30
29	31
30	32
31	33
32	34
33	36
34	38
35	39
36	40
37	41
38	42
39	43
40	44
41	45
42	46
43	48
44	51
45	52
46	53
47	54
48	57
49	58
50	59
51	60
52	61
53	62
54	64
55	65
56	66
57	67
58	68
59	69
60	73
61	77
62	78
63	79
64	80
65	81
66	82
67	84
68	85
69	86
70	87
71	89
72	91
73	97
74	100