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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 38 |
| 5 | 727 |
| 6 | 26013 |
| 7 | 1597690 |
| 8 | 149248656 |
| 9 | 18919743219 |
| 10 | 3005354096360 |
| 11 | 569226803220234 |
| 12 | 124594074249852576 |
| 13 | 30861014504270954737 |
| 14 | 8520443838646833231236 |
| 15 | 2592150684565935977152860 |
| 16 | 861079753184429687852978432 |
| 17 | 310008316267496041749182487881 |