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 | 4 |
| 2 | 36 |
| 3 | 424 |
| 4 | 5716 |
| 5 | 83544 |
| 6 | 1288296 |
| 7 | 20637264 |
| 8 | 340116276 |
| 9 | 5730014584 |
| 10 | 98241641656 |
| 11 | 1708602483504 |
| 12 | 30070563388936 |
| 13 | 534554579527024 |
| 14 | 9584333758817616 |
| 15 | 173120386421418144 |
| 16 | 3147337611202622196 |
| 17 | 57545643875054919864 |
| 18 | 1057492201661230657176 |