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) |
|---|---|
| 3 | 1 |
| 4 | 12 |
| 5 | 83 |
| 6 | 630 |
| 7 | 3171 |
| 8 | 21672 |
| 9 | 97482 |
| 10 | 639180 |
| 11 | 2730615 |
| 12 | 17543196 |
| 13 | 72932904 |
| 14 | 463291920 |
| 15 | 1895949055 |
| 16 | 11961944400 |
| 17 | 48478715240 |
| 18 | 304543085040 |
| 19 | 1226501910315 |
| 20 | 7682898791700 |
| 21 | 30811853728475 |
| 22 | 192632866196694 |
| 23 | 770315837004637 |
| 24 | 4809438625979592 |
| 25 | 19193549752057758 |
| 26 | 119719958370912900 |