A307881 - cp's OEIS frontend

A307881 2a(n) is the least number where k sets a new record such that 2a(n)-k and 2a(n)+k are prime and at least one of 2a(n)-j and 2*a(n)+j is composite for all 0

n	a(n)
1	2
2	4
3	11
4	23
5	64
6	68
7	73
8	119
9	143
10	172
11	263
12	452
13	557
14	868
15	1238
16	1579
17	2864
18	3533
19	3637
20	4252
21	5171
22	9263
23	11282
24	12388
25	20036
26	59119
27	69332
28	90131
29	113783
30	139283
31	178612
32	185714
33	413788
34	468059
35	579932
36	960707
37	1879582
38	2727031
39	3266951
40	3319868
41	3591593

[2, 4, 11, 23, 64, 68, 73, 119, 143, 172, 263, 452, 557, 868, 1238, 1579, 2864, 3533, 3637, 4252, 5171, 9263, 11282, 12388, 20036, 59119, 69332, 90131, 113783, 139283, 178612, 185714, 413788, 468059, 579932, 960707, 1879582, 2727031, 3266951, 3319868, 3591593]

cp's OEIS Frontend

A307881 2a(n) is the least number where k sets a new record such that 2a(n)-k and 2a(n)+k are prime and at least one of 2a(n)-j and 2*a(n)+j is composite for all 0

Table of values

List of values

cp's OEIS Frontend

A307881 2*a(n) is the least number where k sets a new record such that 2*a(n)-k and 2*a(n)+k are prime and at least one of 2*a(n)-j and 2*a(n)+j is composite for all 0

Table of values

List of values

A307881 2a(n) is the least number where k sets a new record such that 2a(n)-k and 2a(n)+k are prime and at least one of 2a(n)-j and 2*a(n)+j is composite for all 0