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 | 6 |
| 3 | 45 |
| 4 | 508 |
| 5 | 7225 |
| 6 | 126306 |
| 7 | 2606065 |
| 8 | 62075952 |
| 9 | 1675774089 |
| 10 | 50565938050 |
| 11 | 1686510607111 |
| 12 | 61609858744248 |
| 13 | 2446470026497705 |
| 14 | 104922088624078194 |
| 15 | 4833250468667819325 |
| 16 | 238004208840601580416 |
| 17 | 12476420334546637657489 |
| 18 | 693675026024580055139778 |