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 | 2 |
| 2 | 16 |
| 3 | 98 |
| 4 | 544 |
| 5 | 2882 |
| 6 | 14896 |
| 7 | 75938 |
| 8 | 384064 |
| 9 | 1933442 |
| 10 | 9706576 |
| 11 | 48650978 |
| 12 | 243609184 |
| 13 | 1219108802 |
| 14 | 6098732656 |
| 15 | 30503229218 |
| 16 | 152544843904 |
| 17 | 762810312962 |
| 18 | 3814309845136 |
| 19 | 19072324066658 |
| 20 | 95363944856224 |