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 | 29 |
| 4 | 265 |
| 5 | 3001 |
| 6 | 42125 |
| 7 | 696149 |
| 8 | 13296145 |
| 9 | 287706481 |
| 10 | 6959431445 |
| 11 | 186061833869 |
| 12 | 5448382252825 |
| 13 | 173418192216361 |
| 14 | 5961442393047965 |
| 15 | 220112963745653189 |
| 16 | 8687730877758518305 |
| 17 | 365023930617143804641 |
| 18 | 16266420334783460443685 |
| 19 | 766297734521812843642109 |