A240301 - cp's OEIS frontend

A240301 a(n) is the number of sets of three positive integers p_1 < p_2 < p_3 such that 2*p_2 = p_1 + p_3, where p_i (i=1,2,3) is either 1 or a prime number and p_3 = prime(n).

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

[1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 2, 3, 1, 3, 3, 2, 2, 4, 3, 4, 4, 4, 2, 3, 4, 3, 3, 5, 5, 5, 4, 5, 4, 5, 4, 5, 5, 6, 4, 4, 7, 4, 6, 7, 6, 7, 5, 4, 5, 4, 6, 8, 7, 7, 7, 7, 4, 8, 9, 8, 5, 9, 6, 7, 8, 4, 8, 8, 10, 8, 6, 6, 10, 9, 9, 7, 7, 6, 9, 10, 9, 8, 8, 12, 13]

cp's OEIS Frontend

A240301 a(n) is the number of sets of three positive integers p_1 < p_2 < p_3 such that 2*p_2 = p_1 + p_3, where p_i (i=1,2,3) is either 1 or a prime number and p_3 = prime(n).

Table of values

List of values

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

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

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