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) |
|---|---|
| 2 | 1 |
| 3 | 6 |
| 4 | 36 |
| 5 | 210 |
| 6 | 1221 |
| 7 | 7098 |
| 8 | 41328 |
| 9 | 241128 |
| 10 | 1409895 |
| 11 | 8260934 |
| 12 | 48497064 |
| 13 | 285219090 |
| 14 | 1680166215 |
| 15 | 9912297150 |
| 16 | 58558256496 |
| 17 | 346371955776 |
| 18 | 2051126447742 |
| 19 | 12158963346852 |
| 20 | 72147074769640 |
| 21 | 428476010502582 |
| 22 | 2546776668682323 |
| 23 | 15149061841758174 |
| 24 | 90175327717962024 |