A187563 - cp's OEIS frontend

A187563 Least k >=0 and k < prime(n) such that prime(n)(prime(n)-k)-1 and prime(n)(prime(n)-k)+1 are twin primes or -1 if no such k exists.

n	a(n)
1	0
2	1
3	-1
4	1
5	-1
6	-1
7	11
8	7
9	17
10	11
11	-1
12	-1
13	11
14	13
15	41
16	-1
17	41
18	-1
19	1
20	11
21	-1
22	-1
23	17
24	41
25	-1
26	23
27	97
28	11
29	7
30	47
31	-1
32	59
33	71
34	1
35	137
36	31
37	97
38	67
39	137
40	119
41	47
42	43
43	101
44	7
45	101
46	91
47	43
48	13
49	11
50	31
51	137
52	71
53	49
54	41
55	137
56	47
57	11
58	61
59	67

[0, 1, -1, 1, -1, -1, 11, 7, 17, 11, -1, -1, 11, 13, 41, -1, 41, -1, 1, 11, -1, -1, 17, 41, -1, 23, 97, 11, 7, 47, -1, 59, 71, 1, 137, 31, 97, 67, 137, 119, 47, 43, 101, 7, 101, 91, 43, 13, 11, 31, 137, 71, 49, 41, 137, 47, 11, 61, 67]

cp's OEIS Frontend

A187563 Least k >=0 and k < prime(n) such that prime(n)(prime(n)-k)-1 and prime(n)(prime(n)-k)+1 are twin primes or -1 if no such k exists.

Table of values

List of values

n	a(n)
1	0
2	1
3	-1
4	1
5	-1
6	-1
7	11
8	7
9	17
10	11
11	-1
12	-1
13	11
14	13
15	41
16	-1
17	41
18	-1
19	1
20	11
21	-1
22	-1
23	17
24	41
25	-1
26	23
27	97
28	11
29	7
30	47
31	-1
32	59
33	71
34	1
35	137
36	31
37	97
38	67
39	137
40	119
41	47
42	43
43	101
44	7
45	101
46	91
47	43
48	13
49	11
50	31
51	137
52	71
53	49
54	41
55	137
56	47
57	11
58	61
59	67

n	a(n)
1	0
2	1
3	-1
4	1
5	-1
6	-1
7	11
8	7
9	17
10	11
11	-1
12	-1
13	11
14	13
15	41
16	-1
17	41
18	-1
19	1
20	11
21	-1
22	-1
23	17
24	41
25	-1
26	23
27	97
28	11
29	7
30	47
31	-1
32	59
33	71
34	1
35	137
36	31
37	97
38	67
39	137
40	119
41	47
42	43
43	101
44	7
45	101
46	91
47	43
48	13
49	11
50	31
51	137
52	71
53	49
54	41
55	137
56	47
57	11
58	61
59	67

cp's OEIS Frontend

A187563 Least k >=0 and k < prime(n) such that prime(n)*(prime(n)-k)-1 and prime(n)*(prime(n)-k)+1 are twin primes or -1 if no such k exists.

Table of values

List of values

A187563 Least k >=0 and k < prime(n) such that prime(n)(prime(n)-k)-1 and prime(n)(prime(n)-k)+1 are twin primes or -1 if no such k exists.

n	a(n)
1	0
2	1
3	-1
4	1
5	-1
6	-1
7	11
8	7
9	17
10	11
11	-1
12	-1
13	11
14	13
15	41
16	-1
17	41
18	-1
19	1
20	11
21	-1
22	-1
23	17
24	41
25	-1
26	23
27	97
28	11
29	7
30	47
31	-1
32	59
33	71
34	1
35	137
36	31
37	97
38	67
39	137
40	119
41	47
42	43
43	101
44	7
45	101
46	91
47	43
48	13
49	11
50	31
51	137
52	71
53	49
54	41
55	137
56	47
57	11
58	61
59	67