A235728 - cp's OEIS frontend

A235728 a(n) = |{0 < k < n - 2: 2m + 1, m(m+1) - prime(m) and m*(m+1) + prime(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	2
7	3
8	2
9	4
10	4
11	4
12	4
13	4
14	5
15	3
16	6
17	4
18	7
19	4
20	3
21	6
22	5
23	6
24	4
25	7
26	4
27	7
28	3
29	5
30	5
31	5
32	6
33	6
34	6
35	3
36	6
37	3
38	4
39	2
40	2
41	4
42	3
43	4
44	5
45	4
46	3
47	6
48	4
49	2
50	4
51	2
52	4
53	3
54	3
55	6
56	4
57	2
58	6
59	8
60	6
61	10
62	4
63	6
64	7
65	4
66	6
67	6
68	8
69	6
70	6
71	2
72	9
73	5
74	9
75	10
76	12
77	4
78	10
79	6
80	10
81	6
82	9
83	5
84	11
85	10
86	7
87	10
88	10
89	6
90	9
91	11
92	7
93	8
94	8
95	13
96	6
97	5
98	5
99	6
100	9

[0, 0, 0, 0, 0, 2, 3, 2, 4, 4, 4, 4, 4, 5, 3, 6, 4, 7, 4, 3, 6, 5, 6, 4, 7, 4, 7, 3, 5, 5, 5, 6, 6, 6, 3, 6, 3, 4, 2, 2, 4, 3, 4, 5, 4, 3, 6, 4, 2, 4, 2, 4, 3, 3, 6, 4, 2, 6, 8, 6, 10, 4, 6, 7, 4, 6, 6, 8, 6, 6, 2, 9, 5, 9, 10, 12, 4, 10, 6, 10, 6, 9, 5, 11, 10, 7, 10, 10, 6, 9, 11, 7, 8, 8, 13, 6, 5, 5, 6, 9]

cp's OEIS Frontend

A235728 a(n) = |{0 < k < n - 2: 2m + 1, m(m+1) - prime(m) and m*(m+1) + prime(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	2
7	3
8	2
9	4
10	4
11	4
12	4
13	4
14	5
15	3
16	6
17	4
18	7
19	4
20	3
21	6
22	5
23	6
24	4
25	7
26	4
27	7
28	3
29	5
30	5
31	5
32	6
33	6
34	6
35	3
36	6
37	3
38	4
39	2
40	2
41	4
42	3
43	4
44	5
45	4
46	3
47	6
48	4
49	2
50	4
51	2
52	4
53	3
54	3
55	6
56	4
57	2
58	6
59	8
60	6
61	10
62	4
63	6
64	7
65	4
66	6
67	6
68	8
69	6
70	6
71	2
72	9
73	5
74	9
75	10
76	12
77	4
78	10
79	6
80	10
81	6
82	9
83	5
84	11
85	10
86	7
87	10
88	10
89	6
90	9
91	11
92	7
93	8
94	8
95	13
96	6
97	5
98	5
99	6
100	9

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

cp's OEIS Frontend

A235728 a(n) = |{0 < k < n - 2: 2*m + 1, m*(m+1) - prime(m) and m*(m+1) + prime(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

A235728 a(n) = |{0 < k < n - 2: 2m + 1, m(m+1) - prime(m) and m*(m+1) + prime(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	2
7	3
8	2
9	4
10	4
11	4
12	4
13	4
14	5
15	3
16	6
17	4
18	7
19	4
20	3
21	6
22	5
23	6
24	4
25	7
26	4
27	7
28	3
29	5
30	5
31	5
32	6
33	6
34	6
35	3
36	6
37	3
38	4
39	2
40	2
41	4
42	3
43	4
44	5
45	4
46	3
47	6
48	4
49	2
50	4
51	2
52	4
53	3
54	3
55	6
56	4
57	2
58	6
59	8
60	6
61	10
62	4
63	6
64	7
65	4
66	6
67	6
68	8
69	6
70	6
71	2
72	9
73	5
74	9
75	10
76	12
77	4
78	10
79	6
80	10
81	6
82	9
83	5
84	11
85	10
86	7
87	10
88	10
89	6
90	9
91	11
92	7
93	8
94	8
95	13
96	6
97	5
98	5
99	6
100	9