A085014 - cp's OEIS frontend

A085014 For p = prime(n), a(n) is the number of primes q such that pq is a base-2 pseudoprime; that is, 2^(pq-1) = 1 mod pq.

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

[0, 0, 0, 1, 0, 1, 1, 2, 1, 3, 2, 1, 3, 2, 2, 4, 1, 2, 3, 5, 4, 3, 6, 4, 4, 6, 4, 5, 4, 6, 5, 4, 2, 5, 8, 7, 5, 6, 3, 3, 3, 4, 5, 4, 4, 5, 9, 8, 7, 8, 5, 8, 7, 8, 4, 6, 6, 7, 7, 9, 6, 11, 7, 8, 2, 7, 12, 8, 6, 8, 4, 5, 5, 6, 5, 11, 10, 9, 11, 5, 8, 9, 12, 9, 4, 7, 13, 8, 5]

cp's OEIS Frontend

A085014 For p = prime(n), a(n) is the number of primes q such that pq is a base-2 pseudoprime; that is, 2^(pq-1) = 1 mod pq.

Table of values

List of values

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

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

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