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 | 0 |
| 2 | 2 |
| 3 | 9 |
| 4 | 36 |
| 5 | 165 |
| 6 | 918 |
| 7 | 6111 |
| 8 | 47304 |
| 9 | 416097 |
| 10 | 4091130 |
| 11 | 44417043 |
| 12 | 527456556 |
| 13 | 6798432069 |
| 14 | 94499679582 |
| 15 | 1408924024695 |
| 16 | 22425642181008 |
| 17 | 379514672913321 |
| 18 | 6804212771165634 |
| 19 | 128827325000617947 |
| 20 | 2568509718703606260 |
| 21 | 53787877376348226573 |
| 22 | 1180349932648067726886 |