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 | 16 |
| 2 | 175 |
| 3 | 1640 |
| 4 | 14189 |
| 5 | 117152 |
| 6 | 939036 |
| 7 | 7379040 |
| 8 | 57188010 |
| 9 | 438810592 |
| 10 | 3342302821 |
| 11 | 25316084248 |
| 12 | 190937278805 |
| 13 | 1435287936320 |
| 14 | 10760879892008 |
| 15 | 80509920297792 |
| 16 | 601343784616830 |
| 17 | 4485466826475360 |
| 18 | 33420579148668670 |
| 19 | 248788060638391120 |
| 20 | 1850652536242372786 |