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 | 40 |
| 3 | 328 |
| 4 | 2536 |
| 5 | 19912 |
| 6 | 158056 |
| 7 | 1260616 |
| 8 | 10073320 |
| 9 | 80551624 |
| 10 | 644308072 |
| 11 | 5154149704 |
| 12 | 41232252904 |
| 13 | 329855188936 |
| 14 | 2638833008488 |
| 15 | 21110638558792 |
| 16 | 168885031942888 |
| 17 | 1351080025960648 |
| 18 | 10808639518937704 |
| 19 | 86469114085259080 |
| 20 | 691752906483344872 |
| 21 | 5534023233270575560 |
| 22 | 44272185810376054120 |