A305629 - cp's OEIS frontend

A305629 Number of values of k, 0 < k < n, for which (2n^2 + 2k*n - k^2 - k)/2 is prime.

n	a(n)
0	0
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	2
9	2
10	2
11	2
12	0
13	3
14	3
15	1
16	3
17	5
18	2
19	2
20	4
21	2
22	1
23	4
24	3
25	2
26	4
27	1
28	4
29	4
30	2
31	4
32	4
33	3
34	1
35	3
36	2
37	4
38	12
39	3
40	2
41	7
42	1
43	7
44	15
45	3
46	4
47	6
48	3
49	8
50	8
51	2
52	4
53	10
54	6
55	7
56	7
57	3
58	6
59	16
60	3
61	4
62	6
63	3
64	8
65	7
66	4
67	5
68	11
69	5
70	4
71	7
72	5
73	8
74	12
75	2
76	12
77	8
78	4
79	16
80	9
81	3
82	8
83	24
84	6
85	8
86	11
87	5
88	8
89	19
90	3

[0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 0, 3, 3, 1, 3, 5, 2, 2, 4, 2, 1, 4, 3, 2, 4, 1, 4, 4, 2, 4, 4, 3, 1, 3, 2, 4, 12, 3, 2, 7, 1, 7, 15, 3, 4, 6, 3, 8, 8, 2, 4, 10, 6, 7, 7, 3, 6, 16, 3, 4, 6, 3, 8, 7, 4, 5, 11, 5, 4, 7, 5, 8, 12, 2, 12, 8, 4, 16, 9, 3, 8, 24, 6, 8, 11, 5, 8, 19, 3]

cp's OEIS Frontend

A305629 Number of values of k, 0 < k < n, for which (2n^2 + 2k*n - k^2 - k)/2 is prime.

Table of values

List of values

n	a(n)
0	0
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	2
9	2
10	2
11	2
12	0
13	3
14	3
15	1
16	3
17	5
18	2
19	2
20	4
21	2
22	1
23	4
24	3
25	2
26	4
27	1
28	4
29	4
30	2
31	4
32	4
33	3
34	1
35	3
36	2
37	4
38	12
39	3
40	2
41	7
42	1
43	7
44	15
45	3
46	4
47	6
48	3
49	8
50	8
51	2
52	4
53	10
54	6
55	7
56	7
57	3
58	6
59	16
60	3
61	4
62	6
63	3
64	8
65	7
66	4
67	5
68	11
69	5
70	4
71	7
72	5
73	8
74	12
75	2
76	12
77	8
78	4
79	16
80	9
81	3
82	8
83	24
84	6
85	8
86	11
87	5
88	8
89	19
90	3

n	a(n)
0	0
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	2
9	2
10	2
11	2
12	0
13	3
14	3
15	1
16	3
17	5
18	2
19	2
20	4
21	2
22	1
23	4
24	3
25	2
26	4
27	1
28	4
29	4
30	2
31	4
32	4
33	3
34	1
35	3
36	2
37	4
38	12
39	3
40	2
41	7
42	1
43	7
44	15
45	3
46	4
47	6
48	3
49	8
50	8
51	2
52	4
53	10
54	6
55	7
56	7
57	3
58	6
59	16
60	3
61	4
62	6
63	3
64	8
65	7
66	4
67	5
68	11
69	5
70	4
71	7
72	5
73	8
74	12
75	2
76	12
77	8
78	4
79	16
80	9
81	3
82	8
83	24
84	6
85	8
86	11
87	5
88	8
89	19
90	3

cp's OEIS Frontend

A305629 Number of values of k, 0 < k < n, for which (2*n^2 + 2*k*n - k^2 - k)/2 is prime.

Table of values

List of values

A305629 Number of values of k, 0 < k < n, for which (2n^2 + 2k*n - k^2 - k)/2 is prime.

n	a(n)
0	0
1	0
2	1
3	1
4	1
5	1
6	1
7	1
8	2
9	2
10	2
11	2
12	0
13	3
14	3
15	1
16	3
17	5
18	2
19	2
20	4
21	2
22	1
23	4
24	3
25	2
26	4
27	1
28	4
29	4
30	2
31	4
32	4
33	3
34	1
35	3
36	2
37	4
38	12
39	3
40	2
41	7
42	1
43	7
44	15
45	3
46	4
47	6
48	3
49	8
50	8
51	2
52	4
53	10
54	6
55	7
56	7
57	3
58	6
59	16
60	3
61	4
62	6
63	3
64	8
65	7
66	4
67	5
68	11
69	5
70	4
71	7
72	5
73	8
74	12
75	2
76	12
77	8
78	4
79	16
80	9
81	3
82	8
83	24
84	6
85	8
86	11
87	5
88	8
89	19
90	3