A236439 - cp's OEIS frontend

A236439 a(n) = |{0 < k < n-2: A000009(m)^2 + A047967(m)^2 is prime with m = k + phi(n-k)/2}|, where phi(.) is Euler's totient function.

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

[0, 0, 0, 1, 2, 3, 3, 2, 2, 2, 1, 1, 1, 1, 2, 2, 1, 1, 4, 2, 3, 2, 3, 5, 4, 3, 2, 6, 6, 4, 2, 1, 8, 4, 4, 3, 1, 6, 4, 3, 3, 3, 3, 3, 4, 4, 5, 3, 4, 5, 3, 3, 7, 4, 5, 5, 5, 11, 7, 6, 3, 7, 8, 6, 5, 5, 8, 6, 7, 11, 7, 5, 7, 8, 7, 7, 5, 10, 10, 5, 6, 8, 6, 10, 8, 6, 8, 11, 10, 6, 10, 7, 7, 9, 4, 9, 11, 8, 13, 7]

cp's OEIS Frontend

A236439 a(n) = |{0 < k < n-2: A000009(m)^2 + A047967(m)^2 is prime with m = 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	1
5	2
6	3
7	3
8	2
9	2
10	2
11	1
12	1
13	1
14	1
15	2
16	2
17	1
18	1
19	4
20	2
21	3
22	2
23	3
24	5
25	4
26	3
27	2
28	6
29	6
30	4
31	2
32	1
33	8
34	4
35	4
36	3
37	1
38	6
39	4
40	3
41	3
42	3
43	3
44	3
45	4
46	4
47	5
48	3
49	4
50	5
51	3
52	3
53	7
54	4
55	5
56	5
57	5
58	11
59	7
60	6
61	3
62	7
63	8
64	6
65	5
66	5
67	8
68	6
69	7
70	11
71	7
72	5
73	7
74	8
75	7
76	7
77	5
78	10
79	10
80	5
81	6
82	8
83	6
84	10
85	8
86	6
87	8
88	11
89	10
90	6
91	10
92	7
93	7
94	9
95	4
96	9
97	11
98	8
99	13
100	7

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

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