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 | 2 |
| 2 | 10 |
| 3 | 72 |
| 4 | 632 |
| 5 | 6352 |
| 6 | 70912 |
| 7 | 864192 |
| 8 | 11371072 |
| 9 | 160333952 |
| 10 | 2409420032 |
| 11 | 38428442112 |
| 12 | 648333665792 |
| 13 | 11538313372672 |
| 14 | 216092576714752 |
| 15 | 4249731095212032 |
| 16 | 87591291183296512 |
| 17 | 1888669450881032192 |