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 | 43 |
| 4 | 525 |
| 5 | 8321 |
| 6 | 162463 |
| 7 | 3774513 |
| 8 | 101808185 |
| 9 | 3129525793 |
| 10 | 108063152091 |
| 11 | 4143297446729 |
| 12 | 174723134310277 |
| 13 | 8039591465487297 |
| 14 | 400924930695585143 |
| 15 | 21543513647508536161 |
| 16 | 1241094846565489688817 |
| 17 | 76314967969651411780673 |
| 18 | 4989260143610128556354611 |