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.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 22 |
| 3 | 151 |
| 4 | 1051 |
| 5 | 7354 |
| 6 | 51472 |
| 7 | 360301 |
| 8 | 2522101 |
| 9 | 17654704 |
| 10 | 123582922 |
| 11 | 865080451 |
| 12 | 6055563151 |
| 13 | 42388942054 |
| 14 | 296722594372 |
| 15 | 2077058160601 |
| 16 | 14539407124201 |
| 17 | 101775849869404 |
| 18 | 712430949085822 |
| 19 | 4987016643600751 |
| 20 | 34909116505205251 |