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 | 27 |
| 2 | 315 |
| 3 | 2534 |
| 4 | 16407 |
| 5 | 91959 |
| 6 | 464723 |
| 7 | 2171850 |
| 8 | 9546570 |
| 9 | 39940460 |
| 10 | 160437690 |
| 11 | 622844730 |
| 12 | 2348773525 |
| 13 | 8638447293 |
| 14 | 31086197469 |
| 15 | 109744786482 |
| 16 | 380920122009 |
| 17 | 1302304276665 |
| 18 | 4392297900647 |