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 | 2 |
| 2 | 23 |
| 3 | 375 |
| 4 | 7138 |
| 5 | 148348 |
| 6 | 3262975 |
| 7 | 74673216 |
| 8 | 1759690865 |
| 9 | 42412172598 |
| 10 | 1040644972314 |
| 11 | 25907046248766 |
| 12 | 652763779424538 |
| 13 | 16614703783094140 |
| 14 | 426563932954831827 |
| 15 | 11033640140115676862 |
| 16 | 287265076610919864178 |
| 17 | 7522060666571155198520 |
| 18 | 197969862318742854908470 |