A130504 - cp's OEIS frontend

A130504 Number of k for which T(n) + T(k) is prime, with 0<=k<=n and triangular number T(n)=n(n+1)/2.

n	a(n)
0	0
1	1
2	1
3	1
4	2
5	0
6	1
7	3
8	1
9	1
10	2
11	1
12	1
13	4
14	0
15	1
16	8
17	2
18	3
19	4
20	1
21	3
22	7
23	3
24	0
25	4
26	3
27	3
28	6
29	2
30	1
31	6
32	2
33	3
34	6
35	2
36	3
37	7
38	4
39	2
40	8
41	2
42	4
43	7
44	2
45	3
46	15
47	5
48	3
49	6
50	2
51	5
52	13
53	5
54	1
55	6
56	2
57	3
58	21
59	3
60	3
61	14
62	3
63	6
64	7
65	2
66	5
67	15
68	6
69	3
70	6
71	5
72	9
73	15
74	4
75	3
76	12
77	3
78	6
79	18
80	3
81	7
82	16
83	4
84	6
85	7
86	7
87	5
88	15
89	1
90	4
91	17
92	5
93	6
94	9
95	7
96	8
97	18
98	6
99	5

[0, 1, 1, 1, 2, 0, 1, 3, 1, 1, 2, 1, 1, 4, 0, 1, 8, 2, 3, 4, 1, 3, 7, 3, 0, 4, 3, 3, 6, 2, 1, 6, 2, 3, 6, 2, 3, 7, 4, 2, 8, 2, 4, 7, 2, 3, 15, 5, 3, 6, 2, 5, 13, 5, 1, 6, 2, 3, 21, 3, 3, 14, 3, 6, 7, 2, 5, 15, 6, 3, 6, 5, 9, 15, 4, 3, 12, 3, 6, 18, 3, 7, 16, 4, 6, 7, 7, 5, 15, 1, 4, 17, 5, 6, 9, 7, 8, 18, 6, 5]

cp's OEIS Frontend

A130504 Number of k for which T(n) + T(k) is prime, with 0<=k<=n and triangular number T(n)=n(n+1)/2.

Table of values

List of values

n	a(n)
0	0
1	1
2	1
3	1
4	2
5	0
6	1
7	3
8	1
9	1
10	2
11	1
12	1
13	4
14	0
15	1
16	8
17	2
18	3
19	4
20	1
21	3
22	7
23	3
24	0
25	4
26	3
27	3
28	6
29	2
30	1
31	6
32	2
33	3
34	6
35	2
36	3
37	7
38	4
39	2
40	8
41	2
42	4
43	7
44	2
45	3
46	15
47	5
48	3
49	6
50	2
51	5
52	13
53	5
54	1
55	6
56	2
57	3
58	21
59	3
60	3
61	14
62	3
63	6
64	7
65	2
66	5
67	15
68	6
69	3
70	6
71	5
72	9
73	15
74	4
75	3
76	12
77	3
78	6
79	18
80	3
81	7
82	16
83	4
84	6
85	7
86	7
87	5
88	15
89	1
90	4
91	17
92	5
93	6
94	9
95	7
96	8
97	18
98	6
99	5

n	a(n)
0	0
1	1
2	1
3	1
4	2
5	0
6	1
7	3
8	1
9	1
10	2
11	1
12	1
13	4
14	0
15	1
16	8
17	2
18	3
19	4
20	1
21	3
22	7
23	3
24	0
25	4
26	3
27	3
28	6
29	2
30	1
31	6
32	2
33	3
34	6
35	2
36	3
37	7
38	4
39	2
40	8
41	2
42	4
43	7
44	2
45	3
46	15
47	5
48	3
49	6
50	2
51	5
52	13
53	5
54	1
55	6
56	2
57	3
58	21
59	3
60	3
61	14
62	3
63	6
64	7
65	2
66	5
67	15
68	6
69	3
70	6
71	5
72	9
73	15
74	4
75	3
76	12
77	3
78	6
79	18
80	3
81	7
82	16
83	4
84	6
85	7
86	7
87	5
88	15
89	1
90	4
91	17
92	5
93	6
94	9
95	7
96	8
97	18
98	6
99	5

n	a(n)
0	0
1	1
2	1
3	1
4	2
5	0
6	1
7	3
8	1
9	1
10	2
11	1
12	1
13	4
14	0
15	1
16	8
17	2
18	3
19	4
20	1
21	3
22	7
23	3
24	0
25	4
26	3
27	3
28	6
29	2
30	1
31	6
32	2
33	3
34	6
35	2
36	3
37	7
38	4
39	2
40	8
41	2
42	4
43	7
44	2
45	3
46	15
47	5
48	3
49	6
50	2
51	5
52	13
53	5
54	1
55	6
56	2
57	3
58	21
59	3
60	3
61	14
62	3
63	6
64	7
65	2
66	5
67	15
68	6
69	3
70	6
71	5
72	9
73	15
74	4
75	3
76	12
77	3
78	6
79	18
80	3
81	7
82	16
83	4
84	6
85	7
86	7
87	5
88	15
89	1
90	4
91	17
92	5
93	6
94	9
95	7
96	8
97	18
98	6
99	5