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 | 3 |
| 3 | 19 |
| 4 | 209 |
| 5 | 3545 |
| 6 | 85803 |
| 7 | 2807723 |
| 8 | 119377321 |
| 9 | 6397099105 |
| 10 | 421772316915 |
| 11 | 33552418294339 |
| 12 | 3168847554832961 |
| 13 | 350514662908385321 |
| 14 | 44885099167514403963 |
| 15 | 6587836555407268741019 |
| 16 | 1098597117953239632728089 |
| 17 | 206564512095561068049417265 |
| 18 | 43495029251774783469442768323 |