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 | 15 |
| 2 | 140 |
| 3 | 995 |
| 4 | 5901 |
| 5 | 30569 |
| 6 | 142375 |
| 7 | 607700 |
| 8 | 2410081 |
| 9 | 8972559 |
| 10 | 31608089 |
| 11 | 106027825 |
| 12 | 340416406 |
| 13 | 1050541069 |
| 14 | 3127340719 |
| 15 | 9007681389 |
| 16 | 25168555576 |
| 17 | 68374424019 |
| 18 | 180958790169 |
| 19 | 467385754264 |
| 20 | 1179927541924 |
| 21 | 2915558734984 |
| 22 | 7060185950979 |