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) |
|---|---|
| 5 | 11 |
| 6 | 71 |
| 7 | 503 |
| 8 | 4031 |
| 9 | 36287 |
| 10 | 362879 |
| 11 | 3991679 |
| 12 | 47900159 |
| 13 | 622702079 |
| 14 | 8717829119 |
| 15 | 130767436799 |
| 16 | 2092278988799 |
| 17 | 35568742809599 |
| 18 | 640237370572799 |
| 19 | 12164510040883199 |
| 20 | 243290200817663999 |