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 | 55 |
| 2 | 1485 |
| 3 | 26235 |
| 4 | 341055 |
| 5 | 3478761 |
| 6 | 28989675 |
| 7 | 202927725 |
| 8 | 1217566350 |
| 9 | 6358402050 |
| 10 | 29248649430 |
| 11 | 119653565850 |
| 12 | 438729741450 |
| 13 | 1451182990950 |
| 14 | 4353548972850 |
| 15 | 11899700525790 |
| 16 | 29749251314475 |
| 17 | 68248282427325 |
| 18 | 144079707346575 |
| 19 | 280576272201225 |
| 20 | 505037289962205 |