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 | 4 |
| 2 | 36 |
| 3 | 984 |
| 4 | 31716 |
| 5 | 1140552 |
| 6 | 43895208 |
| 7 | 1768717872 |
| 8 | 73674176868 |
| 9 | 3146885203432 |
| 10 | 137085166193976 |
| 11 | 6066992348458704 |
| 12 | 272023207778276136 |
| 13 | 12330039492509279184 |
| 14 | 564072488005316830416 |
| 15 | 26010805156782400648800 |