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 | 2 |
| 2 | 6 |
| 3 | 19 |
| 4 | 62 |
| 5 | 207 |
| 6 | 704 |
| 7 | 2431 |
| 8 | 8502 |
| 9 | 30056 |
| 10 | 107236 |
| 11 | 385662 |
| 12 | 1396652 |
| 13 | 5088865 |
| 14 | 18642420 |
| 15 | 68624295 |
| 16 | 253706790 |
| 17 | 941630580 |
| 18 | 3507232740 |
| 19 | 13105289370 |
| 20 | 49114150020 |
| 21 | 184560753390 |
| 22 | 695267483664 |
| 23 | 2625197720454 |
| 24 | 9933364416572 |
| 25 | 37660791173152 |
| 26 | 143048202990504 |