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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 30 |
| 5 | 260 |
| 6 | 5445 |
| 7 | 228564 |
| 8 | 17288852 |
| 9 | 2327095296 |
| 10 | 562985438805 |
| 11 | 248555982382840 |
| 12 | 203515251722217402 |
| 13 | 313711170518065772088 |
| 14 | 922107609498513821505577 |
| 15 | 5221584862895700871908309960 |
| 16 | 57411615463478726571189869693160 |
| 17 | 1232855219250913685154581533108294112 |