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 | 14 |
| 5 | 44 |
| 6 | 148 |
| 7 | 544 |
| 8 | 2400 |
| 9 | 13268 |
| 10 | 73016 |
| 11 | 519252 |
| 12 | 3391406 |
| 13 | 30119132 |
| 14 | 226113492 |
| 15 | 2402746648 |
| 16 | 20167617670 |
| 17 | 252482755188 |
| 18 | 2329941443632 |
| 19 | 33731346482920 |
| 20 | 336826566536064 |
| 21 | 5581686585375024 |
| 22 | 59708797929080240 |