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 | 48 |
| 3 | 760 |
| 4 | 13840 |
| 5 | 273504 |
| 6 | 5703096 |
| 7 | 123519792 |
| 8 | 2751843600 |
| 9 | 62659854400 |
| 10 | 1451780950048 |
| 11 | 34116354472512 |
| 12 | 811208174862904 |
| 13 | 19481055861877120 |
| 14 | 471822589361293680 |
| 15 | 11511531876280913760 |
| 16 | 282665135367572129040 |