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 | 10 |
| 2 | 126 |
| 3 | 1716 |
| 4 | 24310 |
| 5 | 352716 |
| 6 | 5200300 |
| 7 | 77558760 |
| 8 | 1166803110 |
| 9 | 17672631900 |
| 10 | 269128937220 |
| 11 | 4116715363800 |
| 12 | 63205303218876 |
| 13 | 973469712824056 |
| 14 | 15033633249770520 |
| 15 | 232714176627630544 |
| 16 | 3609714217008132870 |
| 17 | 56093138908331422716 |
| 18 | 873065282167813104916 |