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 | 3 |
| 3 | 13 |
| 4 | 65 |
| 5 | 353 |
| 6 | 2024 |
| 7 | 12057 |
| 8 | 73890 |
| 9 | 462851 |
| 10 | 2950261 |
| 11 | 19073921 |
| 12 | 124776881 |
| 13 | 824409052 |
| 14 | 5493384031 |
| 15 | 36874564529 |
| 16 | 249114808794 |
| 17 | 1692489908494 |
| 18 | 11556616157589 |
| 19 | 79265016880139 |
| 20 | 545860966841247 |
| 21 | 3772800724433931 |
| 22 | 26162662010039826 |
| 23 | 181974370638420829 |