A236374 - cp's OEIS frontend

A236374 a(n) = |{0 < k < n: m = phi(k)/2 + phi(n-k)/8 is an integer with 2^(m-1)*phi(m) - 1 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	0
9	0
10	0
11	0
12	0
13	0
14	0
15	0
16	0
17	0
18	0
19	0
20	2
21	2
22	0
23	2
24	1
25	2
26	2
27	2
28	4
29	2
30	1
31	0
32	2
33	1
34	2
35	3
36	3
37	3
38	4
39	2
40	2
41	2
42	3
43	5
44	3
45	4
46	4
47	1
48	1
49	2
50	3
51	7
52	4
53	3
54	5
55	3
56	3
57	2
58	4
59	5
60	4
61	3
62	4
63	3
64	2
65	6
66	7
67	5
68	5
69	4
70	4
71	5
72	4
73	5
74	5
75	3
76	7
77	3
78	5
79	1
80	7
81	4
82	7
83	7
84	5
85	9
86	5
87	9
88	3
89	3
90	5
91	13
92	7
93	9
94	7
95	3
96	4
97	10
98	10
99	9
100	11

[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 2, 1, 2, 2, 2, 4, 2, 1, 0, 2, 1, 2, 3, 3, 3, 4, 2, 2, 2, 3, 5, 3, 4, 4, 1, 1, 2, 3, 7, 4, 3, 5, 3, 3, 2, 4, 5, 4, 3, 4, 3, 2, 6, 7, 5, 5, 4, 4, 5, 4, 5, 5, 3, 7, 3, 5, 1, 7, 4, 7, 7, 5, 9, 5, 9, 3, 3, 5, 13, 7, 9, 7, 3, 4, 10, 10, 9, 11]

cp's OEIS Frontend

A236374 a(n) = |{0 < k < n: m = phi(k)/2 + phi(n-k)/8 is an integer with 2^(m-1)*phi(m) - 1 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	0
9	0
10	0
11	0
12	0
13	0
14	0
15	0
16	0
17	0
18	0
19	0
20	2
21	2
22	0
23	2
24	1
25	2
26	2
27	2
28	4
29	2
30	1
31	0
32	2
33	1
34	2
35	3
36	3
37	3
38	4
39	2
40	2
41	2
42	3
43	5
44	3
45	4
46	4
47	1
48	1
49	2
50	3
51	7
52	4
53	3
54	5
55	3
56	3
57	2
58	4
59	5
60	4
61	3
62	4
63	3
64	2
65	6
66	7
67	5
68	5
69	4
70	4
71	5
72	4
73	5
74	5
75	3
76	7
77	3
78	5
79	1
80	7
81	4
82	7
83	7
84	5
85	9
86	5
87	9
88	3
89	3
90	5
91	13
92	7
93	9
94	7
95	3
96	4
97	10
98	10
99	9
100	11

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

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