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 | 264 |
| 3 | 6588 |
| 4 | 67648 |
| 5 | 390750 |
| 6 | 1739232 |
| 7 | 5765144 |
| 8 | 17318400 |
| 9 | 43224597 |
| 10 | 103158000 |
| 11 | 214360212 |
| 12 | 445665024 |
| 13 | 815732918 |
| 14 | 1521998016 |
| 15 | 2574261000 |
| 16 | 4433514496 |
| 17 | 6975762354 |
| 18 | 11411293608 |
| 19 | 16983569900 |
| 20 | 26433456000 |
| 21 | 37980768672 |
| 22 | 56591095968 |
| 23 | 78310997448 |