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 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 69 |
| 4 | 674 |
| 5 | 7455 |
| 6 | 92540 |
| 7 | 1276569 |
| 8 | 19394870 |
| 9 | 321982323 |
| 10 | 5801055632 |
| 11 | 112753640109 |
| 12 | 2352074473226 |
| 13 | 52419496769991 |
| 14 | 1243115350746404 |
| 15 | 31257697673933889 |
| 16 | 830700701852539742 |
| 17 | 23266435856618600859 |
| 18 | 684997785857198880056 |
| 19 | 21149644833172896698709 |