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 | 0 |
| 1 | 4862 |
| 2 | 2466750 |
| 3 | 63882940 |
| 4 | 670609940 |
| 5 | 4277470470 |
| 6 | 19794795118 |
| 7 | 73143988775 |
| 8 | 228723580800 |
| 9 | 628737007195 |
| 10 | 1559830082888 |
| 11 | 3559370252529 |
| 12 | 7576971259000 |
| 13 | 15210525840125 |
| 14 | 29040055455840 |
| 15 | 53087119860346 |
| 16 | 93432350566520 |
| 17 | 159028880903100 |
| 18 | 262755041438890 |