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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 22 |
| 6 | 100 |
| 7 | 554 |
| 8 | 3654 |
| 9 | 28014 |
| 10 | 244572 |
| 11 | 2392042 |
| 12 | 25877610 |
| 13 | 306553246 |
| 14 | 3944541224 |
| 15 | 54764396346 |
| 16 | 815786104186 |
| 17 | 12976263731454 |
| 18 | 219490418886728 |
| 19 | 3933636232278866 |
| 20 | 74453982353188846 |
| 21 | 1484056255756797222 |
| 22 | 31071499784792496588 |
| 23 | 681729867750992165514 |
| 24 | 15641641334118250802462 |