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 | 59 |
| 4 | 343 |
| 5 | 2302 |
| 6 | 17537 |
| 7 | 149711 |
| 8 | 1417444 |
| 9 | 14755947 |
| 10 | 167664955 |
| 11 | 2066153410 |
| 12 | 27460121377 |
| 13 | 391670868279 |
| 14 | 5969233120520 |
| 15 | 96827494235555 |
| 16 | 1665874346755107 |
| 17 | 30302732222472482 |
| 18 | 581141491978752769 |
| 19 | 11719848107849221435 |
| 20 | 247960209086201040552 |
| 21 | 5491993051193586857235 |