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 | 5 |
| 3 | 71 |
| 4 | 2276 |
| 5 | 144724 |
| 6 | 16688884 |
| 7 | 3249507820 |
| 8 | 1005334796864 |
| 9 | 468967172341824 |
| 10 | 315409074574480704 |
| 11 | 294510517409159769024 |
| 12 | 369877735410388416241920 |
| 13 | 608401340784471133062837504 |
| 14 | 1281569707473914769353921666304 |
| 15 | 3391681347749396029674738480747264 |