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) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 45 |
| 4 | 204 |
| 5 | 1735 |
| 6 | 3640 |
| 7 | 13529 |
| 8 | 22271 |
| 9 | 58302 |
| 10 | 182507 |
| 11 | 250688 |
| 12 | 613046 |
| 13 | 1038538 |
| 14 | 1311167 |
| 15 | 2081983 |
| 16 | 3851401 |
| 17 | 6675916 |
| 18 | 7887193 |
| 19 | 12835857 |
| 20 | 17422352 |
| 21 | 20067757 |
| 22 | 30239982 |
| 23 | 39351402 |
| 24 | 56657043 |
| 25 | 88847952 |
| 26 | 110134459 |
| 27 | 121855019 |