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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 34 |
| 5 | 120 |
| 6 | 434 |
| 7 | 1597 |
| 8 | 5949 |
| 9 | 22363 |
| 10 | 84655 |
| 11 | 322245 |
| 12 | 1232205 |
| 13 | 4729453 |
| 14 | 18210279 |
| 15 | 70307546 |
| 16 | 272087770 |
| 17 | 1055139408 |
| 18 | 4099200524 |
| 19 | 15951053566 |
| 20 | 62159391150 |
| 21 | 242542955378 |
| 22 | 947504851414 |
| 23 | 3705431067156 |
| 24 | 14505084243860 |
| 25 | 56831711106496 |
| 26 | 222853334131080 |