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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 122 |
| 6 | 758 |
| 7 | 5606 |
| 8 | 48378 |
| 9 | 479532 |
| 10 | 5390940 |
| 11 | 68022932 |
| 12 | 954948752 |
| 13 | 14804391270 |
| 14 | 251815549396 |
| 15 | 4673137101108 |
| 16 | 94148342547146 |
| 17 | 2050127343000170 |
| 18 | 48061939075355080 |
| 19 | 1208742383083994580 |
| 20 | 32507565146820336836 |
| 21 | 932149980847656487522 |
| 22 | 28423646163259392354386 |
| 23 | 919399182232129554488328 |