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.

A221740 a(n) = -4*((n-1)*(n+1)^(n+1)+1)/(((-1)^n-3)*n^3).

Table of values

n a(n)
1 1
2 7
3 19
4 293
5 1493
6 38127
7 293479
8 10593529
9 109739369
10 5135610071
11 66987982331
12 3856048810781
13 60693710471869
14 4149140360751583
15 76519827268721103
16 6058888636862818097
17 128138108936443028945
18 11533996620790579909159

List of values

[1, 7, 19, 293, 1493, 38127, 293479, 10593529, 109739369, 5135610071, 66987982331, 3856048810781, 60693710471869, 4149140360751583, 76519827268721103, 6058888636862818097, 128138108936443028945, 11533996620790579909159]