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) |
|---|---|
| 2 | 1 |
| 3 | 16 |
| 4 | 150 |
| 5 | 1104 |
| 6 | 7077 |
| 7 | 41504 |
| 8 | 228810 |
| 9 | 1205520 |
| 10 | 6135690 |
| 11 | 30391520 |
| 12 | 147277676 |
| 13 | 700990752 |
| 14 | 3286733805 |
| 15 | 15215673408 |
| 16 | 69675615234 |
| 17 | 316058238864 |
| 18 | 1421891923038 |
| 19 | 6350464644960 |
| 20 | 28179908990772 |
| 21 | 124327908683616 |
| 22 | 545691921346146 |
| 23 | 2383936774151616 |
| 24 | 10370479696102500 |