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 | 6 |
| 2 | 44 |
| 3 | 280 |
| 4 | 1712 |
| 5 | 10336 |
| 6 | 78528 |
| 7 | 610688 |
| 8 | 4745984 |
| 9 | 28476928 |
| 10 | 173222912 |
| 11 | 1108678656 |
| 12 | 6652604416 |
| 13 | 48774012928 |
| 14 | 292681859072 |
| 15 | 1757200613376 |
| 16 | 11780162781184 |
| 17 | 70685271916544 |
| 18 | 424730711293952 |
| 19 | 3116299774853120 |
| 20 | 19823698692276224 |
| 21 | 120070359807426560 |
| 22 | 720738827865423872 |