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 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 8 |
| 6 | 43 |
| 7 | 225 |
| 8 | 1162 |
| 9 | 6081 |
| 10 | 32315 |
| 11 | 174856 |
| 12 | 961764 |
| 13 | 5369567 |
| 14 | 30373643 |
| 15 | 173811011 |
| 16 | 1004802212 |
| 17 | 5861460314 |
| 18 | 34468644574 |
| 19 | 204161097084 |
| 20 | 1217143092549 |
| 21 | 7299002607829 |
| 22 | 44005589820244 |
| 23 | 266608357403244 |
| 24 | 1622502342468552 |
| 25 | 9914884364399700 |