cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A241535 Smallest semiprime q such that 2*prime(n) - q is semiprime, or a(n)=0 if there is no such q.

Table of values

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

List of values

[0, 0, 4, 4, 0, 4, 9, 4, 21, 9, 4, 9, 25, 4, 9, 15, 25, 4, 15, 9, 4, 15, 21, 9, 9, 15, 4, 9, 4, 9, 33, 9, 9, 4, 9, 4, 9, 21, 15, 25, 35, 4, 21, 4, 33, 4, 9, 9, 9, 4, 15, 9, 4, 9, 9, 9, 9, 4, 9, 9, 4, 21, 25, 25, 4, 51, 33, 25, 9, 4, 9, 15, 21, 9, 9, 21, 15, 9, 9, 15, 21, 4, 21, 4]