A233539 - cp's OEIS frontend

A233539 a(n) = |{0 < k < n-2: m - 1, m + 1, prime(m) - m and prime(m) + m are all prime with m = phi(k) + phi(n-k)/2}|, where phi(.) is Euler's totient function.

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	3
12	2
13	4
14	2
15	4
16	4
17	2
18	4
19	3
20	5
21	1
22	4
23	2
24	3
25	1
26	2
27	2
28	2
29	1
30	1
31	0
32	0
33	1
34	4
35	0
36	1
37	2
38	0
39	5
40	2
41	4
42	4
43	1
44	3
45	3
46	3
47	2
48	3
49	8
50	2
51	2
52	3
53	5
54	5
55	4
56	3
57	5
58	3
59	4
60	3
61	1
62	3
63	8
64	4
65	5
66	4
67	2
68	6
69	0
70	12
71	2
72	4
73	1
74	5
75	0
76	4
77	1
78	4
79	3
80	3
81	2
82	5
83	4
84	7
85	5
86	3
87	11
88	1
89	5
90	4
91	3
92	4
93	6
94	2
95	2
96	5
97	5
98	6
99	4
100	4

[0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 3, 2, 4, 2, 4, 4, 2, 4, 3, 5, 1, 4, 2, 3, 1, 2, 2, 2, 1, 1, 0, 0, 1, 4, 0, 1, 2, 0, 5, 2, 4, 4, 1, 3, 3, 3, 2, 3, 8, 2, 2, 3, 5, 5, 4, 3, 5, 3, 4, 3, 1, 3, 8, 4, 5, 4, 2, 6, 0, 12, 2, 4, 1, 5, 0, 4, 1, 4, 3, 3, 2, 5, 4, 7, 5, 3, 11, 1, 5, 4, 3, 4, 6, 2, 2, 5, 5, 6, 4, 4]

cp's OEIS Frontend

A233539 a(n) = |{0 < k < n-2: m - 1, m + 1, prime(m) - m and prime(m) + m are all prime with m = phi(k) + phi(n-k)/2}|, where phi(.) is Euler's totient function.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	3
12	2
13	4
14	2
15	4
16	4
17	2
18	4
19	3
20	5
21	1
22	4
23	2
24	3
25	1
26	2
27	2
28	2
29	1
30	1
31	0
32	0
33	1
34	4
35	0
36	1
37	2
38	0
39	5
40	2
41	4
42	4
43	1
44	3
45	3
46	3
47	2
48	3
49	8
50	2
51	2
52	3
53	5
54	5
55	4
56	3
57	5
58	3
59	4
60	3
61	1
62	3
63	8
64	4
65	5
66	4
67	2
68	6
69	0
70	12
71	2
72	4
73	1
74	5
75	0
76	4
77	1
78	4
79	3
80	3
81	2
82	5
83	4
84	7
85	5
86	3
87	11
88	1
89	5
90	4
91	3
92	4
93	6
94	2
95	2
96	5
97	5
98	6
99	4
100	4

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	3
12	2
13	4
14	2
15	4
16	4
17	2
18	4
19	3
20	5
21	1
22	4
23	2
24	3
25	1
26	2
27	2
28	2
29	1
30	1
31	0
32	0
33	1
34	4
35	0
36	1
37	2
38	0
39	5
40	2
41	4
42	4
43	1
44	3
45	3
46	3
47	2
48	3
49	8
50	2
51	2
52	3
53	5
54	5
55	4
56	3
57	5
58	3
59	4
60	3
61	1
62	3
63	8
64	4
65	5
66	4
67	2
68	6
69	0
70	12
71	2
72	4
73	1
74	5
75	0
76	4
77	1
78	4
79	3
80	3
81	2
82	5
83	4
84	7
85	5
86	3
87	11
88	1
89	5
90	4
91	3
92	4
93	6
94	2
95	2
96	5
97	5
98	6
99	4
100	4

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	2
9	2
10	2
11	3
12	2
13	4
14	2
15	4
16	4
17	2
18	4
19	3
20	5
21	1
22	4
23	2
24	3
25	1
26	2
27	2
28	2
29	1
30	1
31	0
32	0
33	1
34	4
35	0
36	1
37	2
38	0
39	5
40	2
41	4
42	4
43	1
44	3
45	3
46	3
47	2
48	3
49	8
50	2
51	2
52	3
53	5
54	5
55	4
56	3
57	5
58	3
59	4
60	3
61	1
62	3
63	8
64	4
65	5
66	4
67	2
68	6
69	0
70	12
71	2
72	4
73	1
74	5
75	0
76	4
77	1
78	4
79	3
80	3
81	2
82	5
83	4
84	7
85	5
86	3
87	11
88	1
89	5
90	4
91	3
92	4
93	6
94	2
95	2
96	5
97	5
98	6
99	4
100	4