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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 89 |
| 6 | 382 |
| 7 | 1711 |
| 8 | 7922 |
| 9 | 37663 |
| 10 | 182936 |
| 11 | 904302 |
| 12 | 4535994 |
| 13 | 23034564 |
| 14 | 118209806 |
| 15 | 612165222 |
| 16 | 3195359360 |
| 17 | 16795435994 |
| 18 | 88825567814 |
| 19 | 472356139660 |
| 20 | 2524292893556 |
| 21 | 13549955878141 |
| 22 | 73026827854516 |
| 23 | 395017112175542 |
| 24 | 2143881709415478 |
| 25 | 11671226062503926 |