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 | 3 |
| 2 | 12 |
| 3 | 69 |
| 4 | 612 |
| 5 | 8853 |
| 6 | 217041 |
| 7 | 9245253 |
| 8 | 695682342 |
| 9 | 93580638024 |
| 10 | 22713677612832 |
| 11 | 10025101876435413 |
| 12 | 8100572528598910191 |
| 13 | 12054728928174188426943 |
| 14 | 33214476295395054879355617 |
| 15 | 170255688895444623691322464599 |