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 | 3 |
| 3 | 10 |
| 4 | 66 |
| 5 | 792 |
| 6 | 25506 |
| 7 | 2302938 |
| 8 | 591901884 |
| 9 | 420784762014 |
| 10 | 819833163057369 |
| 11 | 4382639993148435207 |
| 12 | 64588133532185722290294 |
| 13 | 2638572375815762804156666529 |
| 14 | 300400208094064113266621946833097 |
| 15 | 95776892467035669509813163910815022152 |