A236097 - cp's OEIS frontend

A236097 a(n) = |{0 < k < n-2: p = phi(k) + phi(n-k)/2 + 1, prime(p) - p - 1 and prime(p) - p + 1 are all prime}|, 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	1
11	3
12	1
13	1
14	2
15	2
16	3
17	0
18	1
19	1
20	1
21	0
22	0
23	0
24	1
25	0
26	0
27	0
28	1
29	1
30	2
31	0
32	5
33	5
34	2
35	4
36	1
37	5
38	3
39	3
40	2
41	4
42	4
43	9
44	5
45	9
46	4
47	10
48	3
49	6
50	6
51	8
52	5
53	10
54	4
55	4
56	7
57	8
58	10
59	5
60	8
61	9
62	9
63	4
64	11
65	3
66	5
67	5
68	9
69	5
70	4
71	4
72	5
73	6
74	8
75	7
76	6
77	3
78	11
79	4
80	8
81	10
82	9
83	8
84	7
85	6
86	11
87	7
88	9
89	4
90	6
91	5
92	6
93	2
94	9
95	4
96	7
97	6
98	7
99	10
100	9

[0, 0, 0, 0, 0, 0, 0, 2, 2, 1, 3, 1, 1, 2, 2, 3, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 2, 0, 5, 5, 2, 4, 1, 5, 3, 3, 2, 4, 4, 9, 5, 9, 4, 10, 3, 6, 6, 8, 5, 10, 4, 4, 7, 8, 10, 5, 8, 9, 9, 4, 11, 3, 5, 5, 9, 5, 4, 4, 5, 6, 8, 7, 6, 3, 11, 4, 8, 10, 9, 8, 7, 6, 11, 7, 9, 4, 6, 5, 6, 2, 9, 4, 7, 6, 7, 10, 9]

cp's OEIS Frontend

A236097 a(n) = |{0 < k < n-2: p = phi(k) + phi(n-k)/2 + 1, prime(p) - p - 1 and prime(p) - p + 1 are all prime}|, 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	1
11	3
12	1
13	1
14	2
15	2
16	3
17	0
18	1
19	1
20	1
21	0
22	0
23	0
24	1
25	0
26	0
27	0
28	1
29	1
30	2
31	0
32	5
33	5
34	2
35	4
36	1
37	5
38	3
39	3
40	2
41	4
42	4
43	9
44	5
45	9
46	4
47	10
48	3
49	6
50	6
51	8
52	5
53	10
54	4
55	4
56	7
57	8
58	10
59	5
60	8
61	9
62	9
63	4
64	11
65	3
66	5
67	5
68	9
69	5
70	4
71	4
72	5
73	6
74	8
75	7
76	6
77	3
78	11
79	4
80	8
81	10
82	9
83	8
84	7
85	6
86	11
87	7
88	9
89	4
90	6
91	5
92	6
93	2
94	9
95	4
96	7
97	6
98	7
99	10
100	9

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

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