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 | 5 |
| 2 | 18 |
| 3 | 76 |
| 4 | 311 |
| 5 | 1245 |
| 6 | 4882 |
| 7 | 18818 |
| 8 | 71529 |
| 9 | 268785 |
| 10 | 1000422 |
| 11 | 3693814 |
| 12 | 13545669 |
| 13 | 49382777 |
| 14 | 179117070 |
| 15 | 646786228 |
| 16 | 2326351527 |
| 17 | 8338190053 |
| 18 | 29792805066 |
| 19 | 106152792682 |
| 20 | 377267681865 |
| 21 | 1337727360957 |
| 22 | 4733406748722 |
| 23 | 16716506981356 |