A233542 - cp's OEIS frontend

A233542 Number of ways to write n = k^2 + m with k > 0 and m > 0 such that phi(k^2)*phi(m) - 1 is prime, where phi(.) is Euler's totient function (A000010).

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

[0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 2, 3, 3, 3, 2, 4, 2, 2, 2, 4, 3, 1, 2, 4, 4, 4, 3, 2, 4, 2, 3, 3, 2, 3, 4, 4, 5, 4, 4, 2, 1, 3, 4, 5, 4, 4, 3, 1, 6, 5, 5, 5, 2, 4, 4, 3, 2, 3, 4, 5, 4, 5, 4, 2, 3, 6, 4, 3, 5, 6, 3, 4, 6, 3, 4, 6, 6, 4, 4, 3, 8, 1, 3, 6, 5, 5, 4, 2, 2, 4, 5, 4, 5, 2, 5, 6, 3, 4, 6]

cp's OEIS Frontend

A233542 Number of ways to write n = k^2 + m with k > 0 and m > 0 such that phi(k^2)*phi(m) - 1 is prime, where phi(.) is Euler's totient function (A000010).

Table of values

List of values

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

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

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