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.

A291302 a(n) = number of steps to reach a prime when x -> sigma(x)-1 is repeatedly applied to the product of the first n primes, or -1 if no prime is ever reached.

Table of values

n a(n)
1 0
2 1
3 1
4 2
5 1
6 3
7 3
8 1
9 3
10 4
11 46
12 57
13 7
14 9
15 17
16 1
17 45
18 1
19 33
20 8
21 10
22 4
23 3
24 32
25 6
26 47
27 17
28 21
29 41
30 17
31 12
32 11
33 10
34 31
35 74
36 25
37 99
38 11

List of values

[0, 1, 1, 2, 1, 3, 3, 1, 3, 4, 46, 57, 7, 9, 17, 1, 45, 1, 33, 8, 10, 4, 3, 32, 6, 47, 17, 21, 41, 17, 12, 11, 10, 31, 74, 25, 99, 11]