A236472 - cp's OEIS frontend

A236472 a(n) = |{0 < k < n: p = prime(k) + phi(n-k), prime(p) + 2 and prime(p) + 6 are all prime}|, where phi(.) is Euler's totient function.

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

[0, 1, 1, 0, 1, 2, 2, 2, 2, 1, 2, 1, 2, 1, 0, 1, 1, 2, 3, 0, 1, 1, 1, 2, 0, 1, 1, 0, 0, 2, 0, 2, 2, 1, 0, 0, 3, 1, 2, 0, 2, 2, 2, 1, 0, 0, 4, 1, 0, 0, 0, 0, 5, 0, 1, 1, 1, 2, 1, 1, 3, 0, 0, 2, 2, 0, 2, 2, 2, 3, 1, 1, 2, 1, 1, 2, 2, 3, 3, 3, 2, 0, 0, 2, 1, 1, 3, 0, 0, 2, 0, 3, 0, 0, 1, 1, 0, 2, 0, 0]

cp's OEIS Frontend

A236472 a(n) = |{0 < k < n: p = prime(k) + phi(n-k), prime(p) + 2 and prime(p) + 6 are all prime}|, where phi(.) is Euler's totient function.

Table of values

List of values

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

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

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