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.

A238902 a(n) = |{0 < k <= n: pi(pi(k*n)) is a square}|, where pi(x) denotes the number of primes not exceeding x.

Table of values

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

List of values

[1, 2, 1, 1, 2, 3, 2, 1, 2, 4, 3, 4, 3, 3, 3, 2, 5, 5, 4, 3, 5, 4, 5, 4, 5, 5, 6, 4, 4, 6, 4, 5, 4, 6, 4, 4, 3, 4, 4, 3, 4, 4, 4, 4, 5, 3, 4, 5, 4, 3, 4, 5, 5, 4, 2, 2, 3, 2, 3, 3, 3, 1, 4, 3, 4, 3, 3, 3, 5, 2, 1, 2, 3, 5, 3, 4, 4, 2, 1, 5]