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 | 1 |
| 2 | 11 |
| 3 | 76 |
| 4 | 435 |
| 5 | 2255 |
| 6 | 11011 |
| 7 | 51688 |
| 8 | 236028 |
| 9 | 1056210 |
| 10 | 4654430 |
| 11 | 20266312 |
| 12 | 87402185 |
| 13 | 374008635 |
| 14 | 1590144675 |
| 15 | 6724160400 |
| 16 | 28303504680 |
| 17 | 118665923310 |
| 18 | 495820606410 |
| 19 | 2065492595400 |
| 20 | 8581809094950 |
| 21 | 35572994871414 |
| 22 | 147149351758926 |
| 23 | 607555878211376 |
| 24 | 2504288265509800 |