A241536 - cp's OEIS frontend

A241536 Smallest k>=1 such that prime(n)+k and prime(n)-k are both semiprimes, or a(n)=0 if there is no such k.

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

[0, 0, 1, 3, 0, 9, 8, 15, 2, 4, 27, 2, 8, 8, 8, 2, 10, 4, 2, 6, 4, 14, 28, 2, 32, 10, 8, 12, 14, 2, 6, 2, 4, 6, 6, 8, 2, 20, 34, 4, 24, 4, 14, 8, 12, 14, 2, 14, 8, 8, 14, 20, 6, 2, 8, 4, 20, 18, 10, 14, 16, 2, 2, 8, 8, 12, 4, 2, 8, 22, 12, 18, 26, 8, 2, 12, 18]

cp's OEIS Frontend

A241536 Smallest k>=1 such that prime(n)+k and prime(n)-k are both semiprimes, or a(n)=0 if there is no such k.

Table of values

List of values

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

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

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