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 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 10 |
| 6 | 52 |
| 7 | 351 |
| 8 | 3714 |
| 9 | 63638 |
| 10 | 1912203 |
| 11 | 103882478 |
| 12 | 10338614868 |
| 13 | 1892863194064 |
| 14 | 639799762452639 |
| 15 | 400857034314325045 |
| 16 | 467526363203064793081 |
| 17 | 1019286659457016864347582 |
| 18 | 4170114225096278323394128049 |
| 19 | 32130213534058019378134295287305 |